Let me try to explain. Much has been made of how McCain has benefited in his battle against George W. Bush from being able to compete in primaries open to independents and, in some cases, Democrats. And that analysis is valid as far as it goes.
But those open Republican events in Michigan and South Carolina - and this Tuesday in Virginia, North Dakota and Washington state - wouldn't be attracting so many outsiders except for this: There have been no same-day Democratic primaries to keep them occupied.
Consider this past Tuesday in Michigan. How different would the result have been had there been a simultaneous Democratic primary? Surely most of the Democrats and some of the independents who voted in the GOP race - and who went overwhelmingly for McCain - would have opted out of the Republican primary and focused instead on the race between Al Gore and Bill Bradley. Rather than winning comfortably, McCain would have lost decisively.
Most of the time in American politics, both major parties conduct their primaries simultaneously. That's the way it's always worked in Pennsylvania and New Jersey, and it's the way it will work almost exclusively nationwide once we get into March. But February is the great exception, and the Democratic Party has made it so.
The Democrats, unlike the Republicans, have strict rules governing the campaign calendar, and those rules ban all states (except Iowa and New Hampshire) from selecting delegates before March 7. So there haven't been any Democratic primaries since Feb. 1, save for a nonbinding vote in Delaware and one coming up in Washington.
That void has helped McCain immensely, letting him draw support from the available Democrats, even as it has hurt Bradley, who has suffered from not having any real events around which to launch a post-New Hampshire comeback.
The good news for McCain is that February isn't over yet and next Tuesday offers more of the same - primaries open to all comers with no Democratic contest to divert them. The bad news is that most delegates will be picked in March, when Republicans and Democrats conduct primaries simultaneously.
In addition, there are a lot of states coming up with closed primaries, a situation that should favor Bush. Among them are New York, Connecticut, Florida and California, which is its own special case. There, anyone can vote for any candidate, but the outcome among registered Republicans only will determine who gets all the delegates. It is a disaster waiting to happen.
A word about open primaries. Post-Michigan, some Republican analysts have railed against them, making the compelling case that only Republican voters should select the Republican candidate.
One problem. Philosophical arguments aside, 23 states don't have voter registration by party and thus can't conduct closed primaries. Among them are South Carolina and Michigan, which have already voted; Virginia, Washington and North Dakota, coming Tuesday; and in the weeks ahead, Missouri, Georgia, Tennessee, Illinois and Texas. Ohio, which does have party registration, is open as well.
What does any of this mean for the future of the Republican race? Says Bush, "When we have the Republican and the Democratic primary on the same day, it's going to make it awful hard for some of those Democrats who are trying to come into our primary to affect the election."
He's right. But the Republican and Democratic races have interacted several times already this year, and it might happen again. The key is March 7, Super Tuesday.
Assume McCain survives the day (a big assumption) and Bradley doesn't (not so big). The Democratic race disappears, meaning that all those Democrats and independents become available to the Republican insurgent once again, at least in the open primary states.
And if McCain can keep it rolling, there will come a point when the rules won't matter any more.
Larry Eichel's column appears on Wednesdays and Fridays. His e-mail address is firstname.lastname@example.org