Tonight, finally, the presidential primary season comes to an end when polls in Montana and South Dakota close. This longer-than-18-month contest, with its constant barrage of political advertising, 24/7 news networks' analyses and day-after-day print medium coverage, surely has voters worn to a frazzle.

After the polls close, though, people should have a clear-cut idea of whom the Democratic candidate will be. Yes, that's been mentioned enough times already to make pundits sound like Chicken Littles. But, this time, the process is at an end.

Democratic National Committee Chairman Howard Dean, in an April interview on ABC's "Good Morning America," said that, for party unity, one of the two candidates must drop out after today's vote.

Party stalwarts have urged the uncommitted superdelegates to make their selection as soon as the voters have had their say.

By all accounts, the candidate who will emerge on top will be Sen. Barack Obama and the candidate who must drop out will be Sen. Hillary Clinton.

Though this has been an exceedingly close contest between the two, Obama leads in the relevant measures — the delegate count (after Saturday's rules committee decision and Sunday's Puerto Rico primary, he's only 47 delegates short of the nomination while Clinton is 202.5 delegates short) and the popular vote.

Clinton won't yield, though. Her campaign has considered taking the delegate fight to the Credentials Committee at the Democratic National Convention in August and she continues the campaign by saying the nominee should be the one who garnered the most popular votes, vociferously claiming she is the one who has done just that.

But who has the most popular votes depends on how the votes are counted.

In a Monday posting online, Andrew Romano, associate editor and political blogger for Newsweek magazine, did the counting. No matter how you slice the votes — adding in the contested Florida vote, counting the caucus states (votes were not counted there, merely estimated) or leaving out the caucus states — Obama has more popular votes than Clinton.

The only way she can claim to have pulled more popular support than Obama is by including the votes she won in Michigan — a state that disobeyed party rules and moved its primary too early in the year, where both the Clinton and Obama campaigns agreed not to campaign and where Obama's name did not even appear on the ballot.

The Rules Committee decision Saturday to divide Michigan's delegates, and count the delegates from Michigan and Florida as half a vote, should have put an end to Clinton's attempt to renege on her campaign's earlier promises and make a last-minute, desperate bid to keep her all-but-ended campaign breathing.

But Clinton advisers, according to an Associated Press article Sunday, believe the ruling on the Michigan and Florida primaries threatens any possibility of party unity.

Sorry, the only ones threatening party unity in this instance are the Clinton campaign and the candidate herself.

When all the votes are counted — and the only tally that matters here is the tally of delegates — Obama will have reached the magic number needed for nomination. That might rankle people, especially if, by some newer vote tally, Clinton ends up with more popular votes. But that's nothing new. It's how George W. Bush got elected in 2000 — outpolling Al Gore in electoral votes while trailing considerably in the popular vote.

Better ways to determine party candidates and of electing the president can be crafted and should be. But that should be done after the elections, not as the campaigns wind down and certainly not by the courts, as the Supreme Court did in 2000.

Today is Clinton's last hurrah. She cannot win, but this should not be seen as defeat. There is little doubt that, had she not run into the buzz saw of Obama, she would have captured the Democratic presidential nomination as early as February and there is every likelihood she would have become the first sitting female president in this nation.

She might have lost this campaign, but she has done a tremendous service in advancing the cause of women running for and eventually winning the presidency.

That is a legacy worth embracing. She should not tarnish it by pressing a lost cause. If Clinton and her supporters are serious about party unity, then she should depart graciously, pledge support for the Obama candidacy and help end eight years of the disastrous Bush presidency.

— Richard Larsen is a deputy opinion page editor at The Star. His e-mail address is rlarsen@VenturaCountyStar.com.