As wildfires rage through Texas, two of its native politicians are set to pack some rhetorical heat in a GOP debate this evening at the Ronald Reagan Presidential Library in Simi Valley, California. The mass-media narrative will inevitably be pitting second-place Mitt Romney against insta-front-runner, Texas Governor Rick Perry — but the nastiest brawl tonight might actually be between Perry and Texas Rep. Ron Paul.

Perry, who joined the race August 13, is already leading all other contenders by double digit margins according to several recent polls, making him a brightly lit target for his opponents. The Paul campaign took some sharp jabs at him this past week, calling him a “candidate of the week” last Friday. Yesterday, they released the following ad, highlighting Perry’s political background as a Democrat state legislator who in 1988 endorsed then-Senator Al Gore for president:

Ouch.

The Perry campaign sent a sharp volley back though, digging up a letter Rep. Paul wrote in 1987 announcing his resignation from the Republican Party.

In the letter, Paul had harsh words for President Reagan and the GOP:

There is no credibility left for the Republican Party as a force to reduce the size of government. That is the message of the Reagan years…

Thanks to the President and Republican Party, we have lost the chance to reduce the deficit and the spending in a non-crisis fashion. Even worse, big government has been legitimized in a way the Democrats never could have accomplished…

The chickens have yet to come home to roost, but they will, and America will suffer from a Reaganomics that is nothing but warmed-over Keynesianism.

The Perry campaign seized the chance to paint Paul as disingenuous in his associations of President Reagan, releasing the following statement in retort:

Rep. Paul’s letter is a broadside attack on every element of President Reagan’s record and philosophy. Paul thought President Reagan was so bad, he left the GOP … It will be interesting to hear Rep. Paul explain why Reagan drove him from the party at tomorrow’s debate on the grounds of the Reagan Library.

It could be interesting indeed, given that the reasons supplied by Rep. Paul for his resignation mostly alluded to a failure of conservative fidelity on the part of the GOP (a problem he still speaks on in 2011, after being re-elected to Congress as a Republican in 1997).

This afternoon Paul’s campaign chairman, Jesse Benton, fired back yet again at Perry: “We don’t think the fact that you used to be a Democrat is the big problem here.  The real problem is that, too often, you still act like one.  Even you yourself, Governor Perry, said of your party switch, ‘I will still vote the same principles, only with an R after my name.'”

With tensions running this high already, the classic approach of ignoring “crazy old uncle Ron” (hat tip: Jon Stewart) is going to be hard for Perry to pull off tonight, without appearing weak during his prime-time debut. Former frontrunner Mitt Romney will surely be out for Perry’s throat this evening as well. Even with a Texas swagger in his step, and the wind of strong poll numbers at his back, Perry could have a lot to lose this evening.