Power campaigns

While Donald Trump, Hillary Clinton, and Sen. Bernie Sanders, I-Vt., dominate news cycles ahead of summer political conventions, another major campaign unfolds in states across the country: Republicans face a substantial battle to retain control of Congress in the fall.

Democrats need to grab five seats to gain control of the Senate—or just four seats if a Democrat wins the White House. Both The Cook Political Report and the University of Virginia Center for Politics rate seven Senate races as toss-ups, based in part on recent polling data.

Republicans hold six of those seven seats.

Michael Coulter, a political science professor at Grove City College, says Republicans would have faced a tough Senate map this year even without Trump, the presumptive Republican presidential nominee, on the ticket. A handful of the toss-ups are in swing states. (The House seems far less likely to flip, with Democrats needing 30 seats to win, but the party could see gains.)

Will Trump’s high “unfavorable” ratings with voters drag down GOP candidates on the rest of the ballot this fall? Will a substantial chunk of GOP voters stay home? Predictions abound, but Coulter thinks it’s too early to know, particularly since Democratic presidential front-runner Hillary Clinton nearly matches Trump’s levels of unfavorable views among voters, and national polls show a tightening race between the two candidates.

Polls and providence change in unexpected ways during the course of an election season. But with religious liberty, Supreme Court nominations, and other major issues in the balance, Coulter says one thing is certain: “These are crucial elections in American politics.”

Here’s a look at seven potential toss-up races in the Senate that could determine whether the GOP holds on to Congress in the fall:

Illinois

When it comes to Senate races, Sen. Mark Kirk may be the most vulnerable Republican this year. The freshman senator from Illinois faces a tough race for a second term in a state President Barack Obama won by 6 points in 2012.

One of Kirk’s challenges: He doesn’t differ much from Democrats. The pro-abortion, pro-gay-marriage senator joined Democrats last year to oppose a bill defunding Planned Parenthood.

Kirk says he won’t attend the GOP convention this summer, but he will support Trump for at least one strategic reason: Trump could drive up voter turnout in the state. If so, Kirk could reap the benefits of Republican voters pulling a straight ticket.

Trump won the Illinois primary, where voters named job creation as a top issue. The Illinois-based machinery company Caterpillar announced it would cut up to 10,000 jobs by 2018. Mitsubishi Motors said it would shut down its only U.S. plant, based in Normal, Ill. Those are red-meat realities for Trump, who promises to bring jobs back to the United States by imposing high tariffs on imports.

But Kirk faces a tough opponent in a Democrat with a compelling story: U.S. Rep. Tammy Duckworth is a double-amputee veteran of the Iraq War. (She lost both legs in 2004 when Iraqi insurgents hit her Blackhawk helicopter with a rocket-propelled grenade.) The pro-abortion EMILY’s List endorsed Duckworth in the Senate race, and the congresswoman may have a Trump card of her own: Democratic turnout is particularly high in the state during a presidential election.

Wisconsin

Outside of Illinois, Wisconsin is the second state rated by UVA as likely to lose its Republican-held Senate seat to a Democrat in the fall. Republican Sen. Ron Johnson faces a rematch with former Sen. Russ Feingold, a Democrat who held the Wisconsin seat from 1993 until his defeat by Johnson in 2010.

Johnson, a businessman who had never held political office, defeated Feingold in the 2010 election during a tea party wave that swept dozens of Republicans into Congress and returned the U.S. House to GOP control. (Republicans regained control of the Senate in 2014).

Johnson ran as a strident opponent of Obamacare, but he opposed GOP efforts to shut down nonessential parts of the government over defunding the Affordable Care Act in 2013. (Those efforts were led by Sen. Ted Cruz, R-Texas.) Johnson said he opposed Obamacare, but insisted the strategy wouldn’t work. (It didn’t.)

Feingold supported the advent of Obamacare and other Democratic policies for decades. He also joined Sen. John McCain, R-Ariz., in spearheading a controversial campaign finance bill the Supreme Court largely struck down. He voted against the Defense of Marriage Act that Democratic President Bill Clinton signed in 1996. (That measure is dead now too.)

Feingold sees a promising opportunity to regain his former Senate seat, but Johnson is encouraged by voter turnout in the primaries: Some 1.1 million Republicans voted in the state’s primary contest—about 100,000 more than Democrats.

Still, during his campaign for president, Ted Cruz won that contest by 13 percentage points, leaving many wondering whether GOP voters will show up for Trump—and pull the lever for Johnson. At the state’s GOP convention in mid-May, many Republican officeholders didn’t mention Trump by name. (Trump has also had trouble winning over U.S. House Speaker Paul Ryan, a Republican from Wisconsin.)

Wisconsin Gov. Scott Walker told the GOP crowd that turning out voters for Johnson should be their focus, saying holding the Senate was crucial: “That’s where we can have the biggest impact, not just in the state of Wisconsin, but the nation as a whole.”

Ohio

The Buckeye State will host this summer’s Republican National Convention, a four-day event a top Trump aide promised will be “the ultimate reality show.” Meanwhile, reality for incumbent Republican Sen. Rob Portman means he faces a tight battle for reelection in a swing state that could help decide the presidential election as well.

Portman faces off against former Gov. Ted Strickland, a Democrat who lost his post after one term. But Strickland does have name recognition: In a February survey, some 39 percent of Ohio voters said they didn’t know enough about Portman to have an opinion about him. (He’s been a senator for five years.) Only 26 percent said the same about Strickland.

Portman has been a consistent pro-life proponent in the Congress, and he’s led a Senate investigation into an internet company utilized by sex traffickers. But Portman has also changed course on one major issue: In 2013, he declared his support for same-sex marriage after his son announced he was gay. Portman said he wanted to support his child.

So far, Portman has distanced himself from the GOP front-runner. “I am not Donald Trump,” he told Politico. “And no one perceives me as Donald Trump.” It’s a tightrope for Portman: Presidential politics are a decisive factor in voting habits for Ohioans, but Trump lost the state’s primary to Ohio Gov. John Kasich.

Meanwhile, Strickland briefly distanced himself from Hillary Clinton after she commented on promoting clean energy. “We’re going to put a lot of coal miners and coal companies out of business,” said Clinton. That was an unpopular declaration among a dwindling number of coal miners in a state with a long history of coal industry activity.

Pennsylvania

Four days after the confetti drops (or some other spectacle unfolds) at the GOP national convention, Democrats will hold their own meeting in Philadelphia, just after the 240th anniversary of the signing of the Declaration of Independence in the city.

While nothing quite as grand is expected to happen this year, the event will be an important window for Democrats to pitch their case to voters in the swing state Obama won in 2012.

Meanwhile, incumbent Republican Sen. Pat Toomey will continue a close bid to defeat Democratic opponent Katie McGinty. She could be a formidable challenger: In April primaries, McGinty closed a 17-point gap to defeat her Democratic opponent by 10 points.

Now the former chief of staff for Gov. Tom Wolf is seeking to paint Toomey as a Wall Street “wheeler-dealer” more concerned about protecting big money than voters. Toomey—former head of the conservative Club for Growth—dismisses the criticism and says he favors fiscal discipline. In 2013, Toomey argued against raising the national debt ceiling for a simple reason: The U.S. government shouldn’t raise the ceiling to borrow more money to pay interest on other debt.

Toomey also has been willing to criticize Trump when other Republican lawmakers were ducking reporters in the halls of Congress. When Trump called for banning all Muslims from entering the United States, Toomey tweeted: “Trump is wrong. We should not have a religious test for admission to U.S. We should have a security test, and it should be bullet proof.”

New Hampshire

In the bucolic towns of New Hampshire, blazing autumn leaves and clapboard church buildings aren’t the only features of the New England horizon. These days, another reality darkens the landscape: heroin and painkiller addiction.

Abuse of such opioids is the leading health crisis in New Hampshire, and it’s a top campaign issue in a swing state with another Senate race that could help determine whether Congress remains in GOP hands in November.

Republican Sen. Kelly Ayotte is defending her seat against Democratic Gov. Maggie Hassan. Both leaders are popular, and both have tried to spearhead initiatives to battle addiction to painkillers and heroin in the state.

But Ayotte’s opponent is emphasizing a national issue in a bid to unseat the Republican: Gov. Hassan has hammered Ayotte over joining other Republicans in blocking a vote on Merrick Garland, Obama’s nominee for the Supreme Court. Like many other Republicans, Ayotte has said she thinks the Senate should wait until after Election Day to consider a nominee to replace the late Justice Antonin Scalia.

Ayotte won her Senate seat in 2010 despite her objections to same-sex marriage in a state that legalized it in 2009. If she wins another term, it likely would be her last: The senator favors term limits and has vowed never to serve more than two terms in office.

When asked about Trump, Ayotte appeared conflicted: She told reporters she would “support” Trump if he’s the nominee, but said she won’t endorse him. Other lawmakers have made similar distinctions—a position some find confusing. Ayotte recently tried to explain it, saying she would vote for Trump, but she wouldn’t campaign for him.

Florida

With Sen. Marco Rubio, R-Fla., retiring his one-term Senate seat after an unsuccessful presidential bid, the Senate race is wide open in the famously unpredictable swing state. At least five Republicans plan to compete in a primary on Aug. 30, and more could sign up: The deadline is June 24.

Rubio insists he won’t be on the ballot, and he dismisses speculation about running for governor in 2018. In mid-May, the senator was giving signs he might endorse Lt. Gov. Carlos López-Cantera in the race. Like most of the other GOP contenders, López-Cantera promises he won’t get co-opted by Washington.

At least one Republican, U.S. Rep. David Jolly, has resisted the outsider focus. “Why is it in politics that experience and qualifications count against you?” he asked. “Candidates who run as outsiders simply for the sake of being an outsider at some point need to answer for what are their actual skill sets to get things done.”

Two Democrats are vying for a spot on the fall ticket. Vice President Joe Biden recently campaigned for U.S. Rep. Patrick Murphy in Orlando on the home turf of Murphy’s opponent, U.S. Rep. Alan Grayson.

Nevada

The gambling mecca of Nevada may be the GOP’s only chance for moving a state from the Democratic column to Republican control. Republicans are placing their hopes on U.S. Rep. Joe Heck, a brigadier general and a doctor who has won reelection to Congress three times—in a swing district.

Heck faces former Nevada Attorney General Catherine Cortez Masto, who has strong appeal in the state with a large Hispanic population. Cortez Masto would be the first Latina elected to the Senate.

A GOP victory in Nevada would be a huge win for Republicans on another front: Democratic Sen. Harry Reid, the former Senate majority leader, is retiring from Congress after holding his Nevada seat for 30 years.