PARADISE VALLEY, ARIZ., - With new poll numbers that show him trailing fellow GOP candidate Newt Gingrich, Mitt Romney today appeared unfazed, asserting that he "expects to win" but predicting a drawn out contest that will "go on for awhile."

Read the latest ABC News / Washington Post poll.

"You'll see me campaigning aggressively," said Romney, estimating that he has only seven more days of fundraising before he can focus solely on campaign events. "I'll be on the air a good deal more than in the past, doing our very best to communicate to the American people why I'm running for president and hopefully getting their support."

"I know the beginning will be what, January 3rd, but this will probably take longer than a week or two to sort out," predicted Romney.

"My expectation is this campaign that's going to go on for a while and I expect to win it," said Romney. "I need to get something over 1,000 delegates and we're just getting started. I'm pleased with where we are right now, and anticipate getting the nomination if I do my job right."

Holding a rally outside Phoenix, Romney officially received former Vice President Dan Quayle's endorsement. Quayle told the group of about 150 that Romney is the "best hope to change the direction of America."

But despite Quayle's glowing endorsement, Romney was still unable to escape a barrage of questions regarding Gingrich.

At a press availability after the rally, Romney said that the former speaker has his "numbers wrong" when he tries to suggest that Romney's career could make him a "career politician."

On Monday, Gingrich told the press, "I don't know if you ought to count running for Senator in 1984, then running for Governor, then running for President for 6 years, I don't know if that makes him a career politician or not. I'll let you decide."

Romney today shot back, "Actually, he's got the numbers wrong, of course."

"I ran for office but didn't win, that doesn't mean I spent my time in Washington because I didn't win," said Romney. "Had I won, why we wouldn't be having this argument, I would be President of the United States."

And in an interview with Fox News' Neil Cavuto, filmed live in between Romney's rally today and his press conference, Romney vowed "not to be quiet," when it comes to making the differences between himself and Gingrich clear to voters.

"I am going to make sure my message is heard loud and clear," said Romney. "Gingrich is a friend, I respect him, but we have very different life experiences."

"If Americans want someone whose been in Washington the last 40 years, then that's him," said Romney of Gingrich. "But if they want someone whose outside of Washington and a freedom-based society, that kind of experience is I think what it takes. America needs a leader, not so much an insider, but a leader to get America going again."