(CNN) -- Is Super Tuesday the end?
Sens. Barack Obama and Hillary Clinton are fighting for the Democratic nomination.
To paraphrase Winston Churchill, it is not the end, but it is more than the end of the beginning. It is perhaps the beginning of the end.
But with only two or three major candidates left in each party, and with more than half of the country voting, surely both races will be decided on February 5.
Maybe. Maybe not.
The race isn't over until somebody gets a majority of delegates, and both parties have rules that make it difficult to get to a majority.
The Democratic rules award delegates proportional to the vote, so if a candidate gets 40 percent of the vote, he or she gets 40 percent of the delegates.
The winner does not take all. The candidate who comes in second will continue to amass delegates. The candidate who comes in first has to win by overwhelming margins in order to get to a majority quickly.
That seems less and less likely. Polls show Barack Obama gaining momentum as Super Tuesday approaches. Crushing victories by either Hillary Clinton or Obama don't seem to be in the cards.
The fact that most delegates are awarded by congressional district makes it less likely that either Clinton or Obama will sweep the field. Each contender will be able to find pockets of strength in different areas of a state.
And keep this in mind: Many states, including California, allow their residents to start mailing in their ballots weeks before primary day. See who votes on Super Tuesday »
What happens to the thousands of Californians who voted weeks ago for John Edwards or Rudy Giuliani? Tough luck. They wasted their ballots.
The Republican race still has three major candidates, each of whom has won at least one state.
Mike Huckabee is likely to win delegates in states and districts where evangelical voters predominate on February 5. A three-way split makes it harder for a Republican candidate to build a majority.
Past campaigns have seen a reverse bandwagon effect. When a candidate gets close to winning the nomination, the bandwagon doesn't speed up. It slows down.
Voters in the late primaries say, "Oh my God! What have we done?''
That happened to Jimmy Carter twice. In 1976, an "ABC" -- Anybody But Carter -- movement led to late-season victories by Jerry Brown. In 1980, after Carter beat Edward Kennedy in the early primaries, Kennedy started winning.
The race got closer and ended up going all the way to the convention.
It happened in the 1976 Republican race. Gerald Ford defeated Ronald Reagan in the early contests. But when it began to look like Ford had the nomination, Reagan started winning the late primaries. The suspense continued right up to the convention.
If Clinton seems to clinch the nomination Tuesday, watch for a "stop Clinton" movement to emerge in the late primaries, led by Democratic officeholders terrified of running with Clinton at the top of the ticket.
The same thing could happen if John McCain is the big Republican winner on Super Tuesday. Some conservative activists have already signaled an interest in trying to stop McCain in the late primaries. His biggest competition is Mitt Romney, the former Massachusetts governor.
So even if we get apparent nominees on Super Tuesday, the late primaries offer a setting for the final phase of nominating process: voters' remorse. E-mail to a friend