Super Tuesday has finally arrived. With 22 states in play for Democrats and 20 for Republicans, it's the closest thing to a national primary in our electoral history.

The two parties have distinctly different primary methods. Republicans favor a quick winner with some all-or-nothing primaries, while the Democrats' proportional representation system could prolong their primary season for another month, or longer.

Republicans: Crowning McCain?

The Republican race has been tumultuous for the past year. John McCain became the early leader, but others soared ahead of him in the summer and fall. The last laugh and the nomination, however, will go to McCain.

McCain benefitted from the cratering of two possibly difficult contenders: Rudy Giuliani and Fred Thompson. Giuliani had name recognition and support from Fox News' Roger Ailes, while Thompson appeared to answer the right-wing blogosphere's idea of a consistent conservative. As they dropped from sight as credible candidates, McCain's name recognition served him well in securing voters.

The Arizona senator solidified his front-runner status last week in Florida's winner-take-all primary. Florida proved important because it's representative of the GOP's makeup on Super Tuesday: Christian conservatives, fiscal conservatives and national defense conservatives. McCain also captured the delegate lead from Mitt Romney.

McCain has surged in the national polls in recent months, enjoying close to a 20-point lead. McCain also leads in most of the states on Super Tuesday, according to

RealClearPolitics.com poll trackers. His various leads on Monday afternoon stood at: Alabama +6.5%, Arizona +16.3%, Connecticut +22%, Illinois +14%, New Jersey +24% and New York +31%. Most of those states are winner-take-all. McCain could build a huge lead with those states, and an even bigger lead should he win in California.

California offers Romney a slight hope of remaining in the race, because California holds the largest block of delegates at 173. A few recent polls show the race there to be a statistical tie, but Romney really needs more than an upset in California. He also needs Mike Huckabee to beat McCain in some southern states, preventing McCain from running the table.

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This parlay is a big long shot. McCain will probably be the clear Republican nominee come Wednesday.

Democrats: A Close Race Gets Closer

The Democratic race has become a cliffhanger. Obama took the early lead in Iowa but lost it to Hillary Clinton in New Hampshire and Nevada. South Carolina reignited excitement about Obama, though Clinton tempered that with a win in a Florida primary, which doesn't figure into the delegate race, yet.

Clinton has held the lead -- frequently a large one -- in national polls for the last year. But Obama has offset that lead in recent weeks and surged into a statistical tie nationally. Clearly, Obama has the overall momentum.

Some observers attribute this momentum to the media, which made a big deal out of Sen. Ted Kennedy's endorsement last Monday at a rally in Washington, D.C., providing excellent coverage and playing up Obama's parallels to a young John F. Kennedy.

That momentum has helped Obama the most in California. California has become the bluest of the blue states and offers a huge number of delegates: 441. Clinton has long led in the state, so if Obama were to win California, it would be a huge boost to his campaign.

But it wouldn't be a death blow to Clinton.

According RealClearPolitics.com's running average of state polls, Clinton retains leads in many more states than Obama. If she can win in states like Alabama, Arkansas, Connecticut, Massachusetts, Minnesota, New Jersey, New York and Tennessee, then she may well have the delegate lead come Wednesday morning. Many of the small states, however, have had inconsistent and questionable polls at best.

I doubt either Obama or Clinton will hold a big lead in delegates come Wednesday morning. Should the delegate race remain even, it might be hard for Clinton to stop Obama's momentum. Should Clinton come out ahead on Super Tuesday in delegates, then I expect her to win the nomination. She also leads in superdelegates (federal elected officials and party representatives). The combination of those advantages would put Obama in an impossible position.

Political junkies will be glued to the television all day Tuesday, and we should have a better idea of the general election Wednesday morning. My guess is that John McCain will be the Republican nominee, and the Democrats will have more work to do.