Democratic Rep. Kendrick Meek’s Senate campaign released a tough ad Tuesday that uses video clips of Gov. Charlie Crist espousing his Republican bona fides.

“I’m a pro-life, pro-gun, anti-tax Republican,” Crist says in footage that was from before his switch to run for Senate as an Independent. “I think it’s important for people to understand who the true conservative is in this race. And it’s Charlie Crist.”

Crist is trying to siphon Democratic and middle-of-the-road independent votes away from Meek in the three-way Senate race that also features former state Speaker Marco Rubio (R). Rubio’s the favorite at this point. Crist exited the Republican primary earlier this year when it became clear Rubio was becoming the nominee.

The ad demonstrates the difficulties that party switchers have when they abruptly change parties and the change appears politically motivated. Rep. Joe Sestak ran a similarly devastating ad against Sen. Arlen Specter earlier this year in the Pennsylvania Democratic Senate primary. It showed a clip of Specter explaining that he switched from being a Republican to a Democrat in order to get re-elected. Sestak won the primary.