Michigan, Nevada and cross-over voting

The results of tomorrow's Michigan primary and Saturday's Nevada caucuses could depend on the proportion of registered Republicans, Democrats and independents in each party's contest. Just as Obama and John McCain relied on independents to win respectively in Iowa and in New Hampshire, both candidates could get a boost by more cross-over voting this week.

This is especially true in Michigan, where there is effectively no Democratic primary. This means that independents and registered Democrats have nowhere to go but the GOP primary -- and that could very well save McCain's candidacy, as most polls show him trailing Romney badly among registered Republicans. And don't underestimate the number of Democrats who could vote for Republicans tomorrow. The Zogby poll out this morning shows that 22% of the GOP electorate could be Democratic! Race42008 compares the different polls for evidence of the trendline that Romney does best the more GOP voters are included (and this confirms it with the exception of that Mason-Dixon poll). This comparison would seem to indicate that Romney needs about two-thirds of voters tomorrow to be registered Republicans:

Zogby: McCain +3 (50% Republican voters)
Rasmussen: Romney +1 (70% Republican voters)
Mitchell: Romney +2 (75% Republican voters)
Detroit Freep: Romney +5 (83% Republican voters)
MSNBC/Mason-Dixon: Romney +8 (70% Republican voters)

Everyone is now trying to read the tealeaves. And two stories are being talked about right now. First, the weather will not be very good tomorrow in Michigan. It will be freezing with some heavy snow. No storm, certainly, but odds are that some Democrats or independents who cannot be that committed to voting in a GOP primary just stay home; and Romney's supporters being more staunchly Republican, that should reassure him that he will not lose voters because of weather.

Second, the Politico's Jonathan Martin notes a change in voting law in Michigan that could convince some indies and Dems to stay out tomorrow. Until recently, voters could just go in the privacy of the voting booth and only choose then which party they want to participate in. Now, voters have to declare when they enter which ballot they have, with an R or a D written next to their name -- which has to hard to go through for some Democrats, and also for some independents who like to sit on the fence. Martin talks to some voters who declare being worried about this.

And similar dynamics are playing out in the Democratic race. An Obama precinct captain is distributing fliers that try to convince Democrats to change their registration for a day to stop Hillary (who presumably GOPers don't particularly like): "Republicans, Independents, Everyone. You can make the difference if you think a Democrat will win in November and you don't want Hillary...You can come to the Democratic caucus and vote for Obama."

The Obama campaign has since disavowed the flier, but convincing Republicans and independents to vote in the Democratic primary is definitely part of Obama's strategy, and his camp likes to boast that he is expanding the "governing majority." And Clinton regularly takes subtle jabs at Obama's reliance on non-Democrats -- just as Romney is likely to do tomorrow night if McCain wins by swamping the polls with non-Republicans.