John Boehner and Eric Cantor, pictured last June. (Photo by Mark Wilson/Getty Images)

Rep. Eric Cantor R-Va.) currently serves as the House majority leader, a more senior position than House whip (held by Rep. Kevin McCarthy of California) but not as senior as speaker of the House (Ohio's John A. Boehner, of course). With Cantor's primary election loss, attention turns to his inevitable replacement. And, more immediately, the timeline and process for that replacement. How does a party go about choosing its new leader?

With a messy, informal fight, usually. We spoke by phone with Ross Baker, professor of political science at Rutgers University. "This is unprecedented in modern times," he reminds us. "There's not really a schematic that they can follow."

In November 2012, after the elections, as a new class of Republicans was going through orientation on Capitol Hill, the caucus held a vote to reelect Boehner as speaker, Cantor as leader and McCarthy as whip — positions they'd held since the 2010 Republican wave election. But the speaker is the one position that then also requires a vote of the full House. And on Jan. 3, 2013, the first day of the new Congress, that didn't happen without a fight; a number of the more conservative members opposed Boehner in particular.

Now, there's no reason Cantor has to leave his position at this point, given that he's still a member of Congress until next January. But the GOP conference can demand a new election, which Boehner would have to deal with. "Within the Republican conference, there can certainly be a move to accelerate the process," Baker said. "If there were consensus within the conference that this should be done, even if there weren't an obvious [replacement] candidate, they could have an election now." The loss of Cantor makes such a move more likely for another reason, too, Baker pointed out. "Boehner's hand has been weakened by the defeat of his principal lieutenant," Baker said. "A backbench revolt is something we could see. There's the prospect for a very real conflict."

That Cantor was defeated by someone endorsed by tea party activists means that an already tricky succession becomes more loaded. "Normally — and this is probably more true of the Democrats than the Republicans," Baker said, "there's a sort of apostolic succession. The whip would move into the leader position.

"There's going to be a real challenge to Boehner to get the position filled and at the same time mollify the conservatives in the party that want someone more conservative than Cantor," Baker notes. Yet he "can't imagine that the barn-burners in the Republican conference are going to be able to put a candidate forward who's not going to be challenged" by the establishment arm of the party.

"We're really in uncharted waters for the most part," Baker said. But he offered a bit of advice to Boehner. Since the process is informal and can be immediate, they "might as well have the squabble now."