House Republicans were scrambling Tuesday night to determine the fallout on their leadership team and governing agenda after House Majority Leader Eric Cantor was ousted in his GOP primary in Virginia's 7th district.

“I don't know” was the most common refrain among shocked Republican members, senior House aides and GOP operatives when asked to assess the impact of Cantor's defeat. The Virginian, the only Jewish Republican in Congress, was widely viewed as the heir apparent to House Speaker John Boehner, R-Ohio, and for most of his political career was considered at the forefront of the more conservative party the GOP has become.

One House Republican, who spoke on the condition of anonymity, said Cantor's loss was a “big win” for President Obama because it could empower the more hardline elements in the GOP and damage the effort on the part of some Republicans to broaden the party's appeal to cross ethnic and gender lines. Cantor lost to college professor Dave Brat, who campaigned as an anti-immigration reform candidate and affiliated with activists and talk radio hosts who identify with the Tea Party.

“It really is shocking; completely shocking,” the House Republican said.

Of immediate concern to House Republicans and their allies was how Cantor’s loss would affect the senior leadership team and the party’s election prospects.

Some Republicans speculated that Cantor could step down as House majority leader, the GOP conference’s No. 2 leadership post, within days. However, the more likely outcome appeared to be that Cantor would serve out his term, which runs through the end of the year, concurrent with his congressional term. That way, Republicans would maintain stability and prevent a bloody intraparty fight for Cantor’s position that could be great political fodder for Democrats.

“I think he stays on,” a Republican lobbyist said. “If we had an open fight now when things are going our way [in the midterm campaign], it would be a distraction for our conference — it would be extremely divisive.”

Still, a competitive race for majority leader is likely to ensue immediately. The insurgent Tea Party members in the House Republican conference are also likely to feel emboldened to run for leadership -- or to at least deny Boehner another term as speaker. Those conservatives had been hoping that House Financial Services Chairman Jeb Hensarling would challenge Boehner, but he has signaled privately that he has no intention of doing so. Some believe that could change.

“It's going to be a full-on brawl between the Tea Party and the establishment for control of the leadership. This victory is the 'Pulp Fiction' equivalent of the adrenaline needle plunged into the chest of the Tea Party,” said Ron Bonjean, a Republican consultant who previously served as a leadership aide in the House and Senate.

Where many House Republicans predicted stability heading into next year, with Boehner either remaining on the job or Cantor replacing him if he stepped down, all senior leadership positions could now be in play, multiple Republican sources told the Washington Examiner. One House GOP aide said the next few months could be “total f---ing chaos” as members campaigned against each other for speaker, majority leader, majority whip and other leadership posts.

Cantor's departure opens the door for multiple positions to be in play in the fall, even if Boehner decides to remain as speaker and has the votes to keep the gavel. At the very least, a spirited contest for majority leader is on tap and likely a race for majority whip, as House Majority Whip Kevin McCarthy, R-Calif., has long coveted a promotion.

Members to watch who have been mentioned as ambitious to enter the Republican leadership, or those in leadership who want to move up, include: House Majority Chief Deputy Whip Peter Roskam of Illinois, House Republican Conference Chairwoman Cathy McMorris Rodgers of Washington, House Rules Chairman Pete Sessions of Texas, Republican Study Committee Chairman Steve Scalise of Louisiana, Rep. Tom Price of Georgia and Rep. Ann Wagner of Missouri, among others.

And expect House Budget Chairman Paul Ryan of Wisconsin to be mentioned again. The 2012 GOP vice presidential nominee is on track to become House Ways and Means chairman next year, but Republicans could look to him to fill the void in leadership left by Cantor because he is a unifying figure. Ryan has never had any interest in serving in a senior conference leadership position.