The one to watch?

What if you gave a party and nobody came? That may be how John Kerry felt on March 16, the night he won the Illinois primary and collected his 2,162nd delegate-enough to finally change his title from &quotDemocratic front-runner" to &quotDemocratic nominee."

With no serious opponents still in the race, however, the national media virtually ignored Mr. Kerry's anticlimactic win. Far more interesting-and potentially more important-was the 15-way primary to replace retiring Sen. Peter Fitzgerald, a rare Republican officeholder in an increasingly Democratic state. National Democrats see Illinois as perhaps their best hope for helping to erase the GOP's two-seat majority in the Senate.

Their surprise nominee is Barack Obama, an African-American state senator from Chicago's gritty South Side. Mr. Obama, once far back in the pack of seven Democratic hopefuls, surged in the final month as he consolidated support among black voters and liberal whites. He finished with just better than 50 percent of the vote, despite the unusually crowded field.

Unusually crowded and extraordinarily rich. Out of 15 candidates running in both the Democratic and Republican primaries, seven were millionaires with the means to bid up their ambitions. Inspired, perhaps, by Mr. Fitzgerald's self-funded upset of Sen. Carol Moseley-Braun in 1998, the candidates shattered spending records in their effort to buy the open seat.

Some of those efforts were more successful than others. Mr. Obama was one of the nonmillionaires, yet he trounced businessman Blair Hull, the biggest spender from either party. Mr. Hull, who sold his brokerage business for $531 million, is reportedly the richest person ever to run for office in Illinois. He got off to a quick start, soaring to the top of the polls, thanks to months of constant TV ads he purchased with some $30 million of his own money. That also bought him a $20,000-a-month campaign manager, a paid staff of 140, and an army of $75-a-day yard-sign distributors (a task normally performed by volunteers).

What it couldn't buy him was a victory. His campaign imploded after media pressure forced him to unseal his divorce records, revealing charges he had struck his ex-wife and verbally threatened her. Mr. Hull finished with just 11 percent of the vote.

The richest Republican in the race fared much better. Jack Ryan, a former investment banker who left his profession to teach at an inner-city Catholic school, beat out seven other Republicans to claim the nomination. With a net worth of up to $96 million, he poured some $3.5 million of his own money into the campaign, conserving millions more for the general election. Two other wealthy Republicans, dairy owner Jim Oberweis and businessman Andy McKenna, spent $3 million and $2.4 million respectively.

Given his compelling biography, Mr. Ryan was able to position himself convincingly as a compassionate conservative. He campaigned for tax cuts, but always in terms of how lower taxes would create more jobs. Likewise, he championed school choice as the best hope for low-income families trying to give their children a better future. He found surprising support for his message among some black church leaders, giving rise to GOP hopes that he might have crossover appeal in the general election.

In the ugly, expensive campaign yet to come, however, Mr. Ryan may be dogged by rumors about his divorce from actress Jeri Ryan of Star Trek: Voyager and Boston Public. Like Mr. Hull, Mr. Ryan had his records sealed, but unlike the Democrat, he steadfastly refused to open them despite pressure from the media and many within his own party. Mr. Ryan said the papers should remain sealed to protect his 9-year-old son, but some GOP leaders fear a last-minute leak of any damaging information could doom his campaign come November.