Before there was Karl Rove, there was another political operative whose name became synonymous with the President he helped get elected: James Carville. The Ragin' Cajun has had many a phrase adopted into the political world's lexicon, most famously the now much over-used cliche "it's the economy, stupid." But there is another one more apropos for the latest (and hopefully last) GOP Presidential primary debate: "if you 'splainin', you losin.'"

Rick Santorum: take note. During the mostly painful and often awkward debate, the former US Senator did something that simply doesn't work in political debates — trying to explain away a bad vote. 

Remember John Kerry's infamous remark about voting for the $87 billion before voting against it? Of course you do, as it came to define his failed candidacy. 

The only thing worse than trying to explain a bad vote in politics is trying to explain a bad vote using legi-speak. Legi-speak, like legalese, is about as effective in debates as Klingon is in trying to pick up chicks at a college bar. 

Future candidates take note: don't do it. 

In trying to explain that his vote for No Child Left Behind was against his principles, but he did it anyway because he's a "team player," Santorum painted himself in the most unflattering light for a GOP primary candidate. If the 2010 election taught us anything, it's that the GOP primary electorate does not like "go along to get along" candidates, as Ron Paul viciously slammed Santorum. 

In running for President, you are running to lead the team, not just be a part of it.

Later on, Santorum continued to engage in explanation politics, claiming his support of Republican turncoat Arlen Specter was actually a helpful move to help get President Bush's Supreme Court nominees through the Senate. 

Again, not a smart move. 

Don't ever defend your support of a traitor — especially to the very audience he turned against.

What Santorum should have done, and his staff should have prepped him to do, is attack Romney for supporting a less-than-rock-ribbed-conservative candidate. With the amount of endorsements Romney has made over the years, there must be a handful he wouldn't be so proud to be associated with anymore.

In that regard, he should take another lesson from the Ragin' Cajun.

The other guy can't attack you if he's got your fist in his face. 

(Photo Credit: AP/CBS News)