Newt Gingrich, who remains in the race for the 2012 GOP presidential nomination, conceded Sunday that his rival Mitt Romney was about as close as it gets to becoming the party's presidential nominee.

"I think you have to be realistic," Gingrich said on "Fox News Sunday." The former House speaker was responding to a question about his intentions going forward in the Republican nominating fight.

"Given the size of his organization, given the number of primaries he's won, he is far and away the most likely Republican nominee," Gingrich said of Romney, a former governor of Massachusetts. "If he does get to 1,144 delegates, I'll support him. I'll do everything I can this fall to help him beat President Obama. The entire goal of the Republican primary has to be to defeat Barack Obama. It's what makes this probably the most important election of our lifetime."

Gingrich's organization announced in early April it was reducing the size of its staff and cutting back on the number of campaign stops, choosing to focus instead on wooing delegates to August's Republican National Convention in Tampa.

On Sunday, Gingrich said he would use any influence remaining to help determine the platform of the GOP.

"I think platforms matter in the long-term evolution of the party," Gingrich said. "The party is more than just the presidential candidate."

The candidate cited energy independence, social security reform, and religious liberty as issues he would advocate for at the Republican convention.

Despite the now-long odds of becoming the GOP nominee, Gingrich said he was happy he made his bid.

"I'm glad I did this," he said. "For me it was important as a citizen to try to do some very hard things. To try to bring new ideas and new approaches. It turned out to be much harder than I thought it would be, but it was the right thing for me to do, both in my life and where I thought the country was. I have no regrets."

The power of Romney's powerful organization, bolstered by many in the Republican establishment, proved difficult to overcome, Gingrich said.

"It's clear Gov. Romney did a very good job of building a very substantial machine. And I think as Santorum is discovering in Pennsylvania right now, it's a challenge," he said.

Gingrich added that a powerful negative ad campaign from Romney and his supportive super PAC eventually wore away at his presidential prospects.

"I hit him as hard as I could, he hit me hard as he could," he said. "Turns out he had more things to hit with than I did. And that's part of the business."