Predicting Pennsylvania

After weeks of bad bowling, whiskey-imbibing, attacks, counter-attacks, and talk of bitter, small-town voters, the Pennsylvania primary comes to a resolution - or at least a vote - today. Here's your key to the Pennsylvania primary.

POLLS

Clinton started with a 14-point lead at the end of February. Obama narrowed that lead and today, Clinton has a Real Clear Politics Average lead of 6.1%. The race may come down to undecided voters and who turns out to vote.

KEY VOTER GROUPS

A candidate's ability to capture these groups helps predict electability in November.

White Catholics. According to a Quinnipiac University poll, Clinton leads Obama 66-29% among this group, which is also key in the general election. Obama became the first presidential candidate to hire a fulltime Catholic outreach director and got endorsements from some prominent Catholics, but God-o-Meter wonders if Catholic reticence could be Obama's biggest stumbling block in November.

White, working-class men. WSJ says they're a swing constituency with a growing concern about the economy, and Hillary Clinton leads 49% to Obama's 44%. Obama usually leads among white men, and Quinnipiac University gives Obama a lead (53-42%) among all men.

Rural, small-town voters.This is the group Obama seemed to disparage when he said, "And it's not surprising then they get bitter, they cling to guns or religion or antipathy to people who aren't like them." Obama's comments seemed to make little difference in the polls, but Clinton leads among rural Democrats 58% to Obama's 37%.

DEFINING VICTORY

Pundits say an Obama win might mean Clinton dropping out, but most expect a Clinton win. The margin of victory is relevant, though. According to the Wall Street Journal, former DNC chair Steve Grossman defines a "convincing victory" as a five-point win. The Los Angeles Times puts it at 10 points. Salon says Gov. Rendell deems a 6-7 point Clinton win "tremendous." Mother Jones Blog splits the difference: "Over 7, victory for Clinton. Under 5, victory for Obama. Anywhere from 5 to 7 and we call it a draw." Clinton shrugged it off today: "I don't think the margin matters."

Delegates make a difference, too. Obama is about 377 pledged delegates from winning the 2,025 he needs to clinch the nomination. He's 139 delegates ahead, and even if Clinton wins the popular vote, she probably won't get the delegates she needs to close that lead. The Washington Post crunches the numbers and says the candidates could evenly split the delegates.