Unity Bounces in Virginia and New Jersey?

As it turned out, there was a unity bounce after Barack Obama secured the nomination. In the short-term, he gained a few points in the polls.

Now, with gubernatorial primaries in New Jersey and Virginia coming up in June, I'm wondering whether we'll see a repeat of that phenomenon.

My theory of unity bounces is that they only occur under limited circumstances. If a primary battle is really bitter and the candidates represent dramatically different ideological perspectives, then an immediate bounce is unlikely. Under those circumstances, it may take weeks or months to patch the party back together. It might not happen at all.

On the flip side, a unity bounce is also unlikely if the competing primary candidates all seem exactly alike and don't stir strong passions. In those cases, why wouldn't a party's voters have been telling pollsters all along that they would support the nominee?

What made the 2008 Democratic presidential nomination ripe for a unity bounce was that some Democrats were really passionate about Hillary Clinton and not particularly fond of Obama. Some of these people were so loyal to Clinton that when asked by a pollster about the general election, they couldn't bring themselves to say they would vote for the Illinois senator.

Yet, in the end, the differences between Clinton and Obama were pretty small. Clinton endorsed Obama, leading most of her supporters to back Obama rather quickly.

The circumstances look a bit different in New Jersey and Virginia. In New Jersey, two Republicans are squaring off to face Gov. Jon Corzine. Chris Christie is the insider with a moderate reputation, while Steve Lonegan is the conservative outsider. The perceived gap between them is large enough that I'm not sure the loser's supporters will rally behind the winner.

In Virginia, the Democrats are the ones with a contested nomination. Terry McAuliffe, Creigh Deeds and Brian Moran have stylistic differences, but they don't differ enough on the issues to represent different wings of the party. In fact, the differences between them are small enough that many Virginia Democrats are most concerned with picking the most electable candidate. Loyal Democratic partisans (as opposed to moderate-to-conservative Democrats who sometimes vote Republican) are probably already on board with any of the three, making a unity bounce unlikely.

That's my sense anyway. The science of unity bounces certainly isn't exact.