A rivalry is brewing between Rick Perry and Ron Paul, a politician that many observers see as having no chance of being elected president in the 2012 election.

The two politicians from Texas have never had much of a relationship and Paul has refrained from criticizing his home state governor. But all that changed last weekend.

Paul took the first shot.

“The only thing I would advise is looking into him, looking at his record, and not just taking him at face value,” Paul said in an interview with The Associated Press. “Texas has had a lot of changes in these last eight years, not exactly positive either.”

And on Tuesday, the Paul campaign issued a new campaign ad directly attacking Perry as an Al Gore cheerleader.

In the ad, “Trust,” which will run twice nationally during tonight’s NBC/Politico Republican debate, Paul says Perry helped lead Gore’s 1988 campaign.

But instead of ignoring his fellow GOP hopeful, the Perry campaign struck back.

Perry said he didn’t serve as Gore’s cheerleader, adding that he endorsed Gore but never served as Texas chair of his campaign.

The Perry campaign pushed back further against another claim in the ad — that Paul carries on Reagan’s legacy and was an early supporter of the former president during his 1976 primary challenge against Gerald Ford.

“Paul thought President Reagan was so bad, he left the GOP,” Perry spokesman Mark Miner wrote, referring to Paul’s 1988 bid for president on the Libertarian ticket.

Craig Shirley, a longtime Republican operative and Reagan scholar, also rejected Paul’s claim, saying he didn’t play a large role in Reagan’s 1976 primary challenge to President Gerald Ford.

Today, Paul’s campaign chairman, Jesse Benton, hit back against Perry in a news release, claiming that the real issue is that the Texas governor still acts like a Democrat. Benton questioned Perry’s record as a conservative, noting Perry’s support for the federal bailout and stimulus funds, his support of welfare for illegal immigrants, and for twice raising taxes and doubling the state’s debt during his tenure as governor.

A fact check of Perry’s record found most of those claims to be true.

Perry did accept some stimulus money, he implemented a Texas version of the DREAM Act, Perry voted for the largest tax increase in Texas state history in 1987 and supported $528 million tax hike in 1990. And the claim that state debt has more than doubled during Perry’s tenure is true.

The Perry campaign did not immediately respond to ABC News for reaction.

Ron Paul isn’t the only one questioning Rick Perry’s record. Rep. Steve King, R-Iowa, predicted on “Top Line” that Perry’s “momentum will diminish” as voters get to know him and his record.

King said he’s particularly interested to learn more about “the continuum of the transformation of Rick Perry from, apparently, a Democrat to a Republican.”

A recent CNN poll showed Perry’s ascendancy to the top of the GOP field is coming at a cost to Paul. The Texas representative dropped 6 points compared to early August and 8 points when tested without Sarah Palin or Rudy Giuliani.