As Republicans confronted President Obama in another budget battle last week, their leadership included another new face: Representative Eric Cantor of Virginia, who as the party’s chief vote wrangler is as responsible as anyone for the tough line the party has taken in this first legislative standoff with Mr. Obama. This battle has vaulted Mr. Cantor to the front lines of his party as it tries to recover from the losses of November.

As Republican whip, Mr. Cantor succeeded again on Friday in denying the White House the support of a single House Republican on the stimulus bill. That was a calculated challenge to the president who, in his weekly address on Saturday, hailed the bill as “an ambitious plan at a time we badly need it.”