House Majority Leader Eric Cantor (R-Va.) backed former Massachusetts Gov. Mitt Romney’s campaign today, marking the highest-ranking GOP House Member to pick sides in the presidential race.

“I cast my vote already in Virginia for Mitt Romney,” Cantor told David Gregory on NBC’s “Meet the Press.” “And I’m here today to tell you that I’m endorsing Mitt Romney in his candidacy for the presidency of the United States.”

Cantor’s proclamation came less than two days before polls open in Virginia and the 10 other states with Super Tuesday contests. There are 424 delegates at stake as well on Tuesday.

Romney’s opponents defended their position ahead of Super Tuesday in various interviews with television networks today.

Fresh off a narrow loss in Michigan, former Sen. Rick Santorum (R-Pa.) said he’d do better in the primary contests if former Speaker Newt Gingrich left the race. Santorum said that he would have defeated Romney in Michigan if he had all of Gingrich’s minimal support in that primary.

“We have the anti-Romney vote, if you will, both Gingrich and I are out there slugging away,” Santorum said on “Fox News Sunday.” “We’re the ones who are the clear alternative, and eventually, hopefully, this race settles out, and we’ll get a chance to go one on one. And once that happens, we feel very comfortable we’re going to win this thing.”

Santorum also expressed confidence that he would perform well in many of the states holding contests on Tuesday, especially in Ohio. Santorum failed the ballot requirements in some parts of the Buckeye State, so he is ineligible for 18 of the state’s 66 delegates this week. Neither Santorum or Gingrich made the Virginia ballot.

“If you look at all of the states, other than a handful in Ohio, and Virginia, where we weren’t the only ones who didn’t get on,” Santorum said. “We’ve done amazingly well for a campaign who early on didn’t have a lot of resources to go out and do things.”

Gingrich argued his case in three television interviews on the Sunday morning TV circuit. The Georgia Republican was repeatedly pressed on whether he could continue in the race after Super Tuesday, especially if he lost his home state.

“This is going to go on for a good while,” Gingrich told George Stephanopoulos on ABC’s “This Week.” “Gov. Romney, who’s outspent all the rest of us by multiples, is a frontrunner without any question, but I think he’s not a very convincing frontrunner, and he’s a long way from having closed out this race.”

Gingrich also drew a contrast between his policies and those of Santorum, arguing that the former Pennsylvania Senator’s ties to labor unions play well in the industrial states but not in the South.

“Santorum has been historically a labor union Senator from Pennsylvania,” Gingrich said on “This Week.” “He voted against national right to work. He voted for [the Davis-Bacon Act], which cost state and local governments billions of dollars in favor of unions. And he voted for every single minimum wage increase that the unions asked for. … And when you get out of the industrial states, I think it gets harder for Rick to put together a majority, so we’ll see how it goes next Tuesday.”