ORLANDO, Fla. — Newt Gingrich has been predicting that the battle for the Republican presidential nomination will last “until June or July, unless Romney drops out sooner,” but the magnitude of his loss to Mitt Romney in Florida’s primary on Tuesday could force him to recalibrate.

It is possible, of course, that the contest will stretch on for several months, largely because the voting so far has allocated only 5 percent of the delegates needed to claim the nomination. On Wednesday, the battle turns to states like Nevada that award their delegates on a proportional basis, so even coming in second will have a payoff, unlike in Florida, where the winner takes all.

But Mr. Gingrich’s loss in Florida was a profound rejection of his candidacy by voters in one of the biggest, most important swing states, and pressure could mount on Mr. Gingrich to drop his insurgency bid.

Still, he said he would not back down. Framed by signs that read “46 states to go,” Mr. Gingrich told supporters at a convention center ballroom here on Tuesday night: “We are going to contest every place, and we will win.”