(CNN) - Mitt Romney, pushing back against the charge he isn't conservative enough for the GOP base, released a radio ad in Colorado Wednesday asserting his appeal among a few well-known Republicans.
The ad, titled "Conservative Leader," will begin airing in Colorado Wednesday. That state holds caucuses February 7.
Follow the Ticker on Twitter: @PoliticalTicker
"This is the most important election of our lifetime and conservatives across America are supporting Mitt Romney," an announcer says before introducing a quote from New Jersey Gov. Chris Christie, who has endorsed Romney.
"America cannot survive another four years of Barack Obama and Mitt Romney is the man we need to lead America and we need him now," Christie says.
The announcer then introduces conservative firebrand Ann Coulter, who says: "I think it's going to be Romney, I think Romney is the strongest candidate, and I think Republicans want to beat Obama, and Romney is the best one to do that."
Coulter's quote is from a November appearance on Fox News.
A last quote comes from Leondray Gholston, a Romney supporter and the candidate's Colorado grassroots chairman.
"He's a proven executive, an accomplished private sector businessman and a man of courage and vision," Gholston says. "As a patriot, a conservative, and a person with deep affection for our Constitution and country, I urge and argue most fervently for the election of Mitt Romney as our Republican nominee and next President of the United States."
Romney won Colorado in 2008 with 60% of the vote.