South Carolina Congressman Trey Gowdy opened up for Marco Rubio, telling voters in his state of the strength of the freshman Senator’s conservative record.

“There is no one more conservative than Marco Rubio,” Gowdy said, pointing out that Rubio had a higher Heritage Action score than either Sen. Jeff Sessions of Alabama or Rep. Steve King of Iowa. Both those men have a strong record of opposing amnesty for illegal immigrants.

According the Heritage scorecard, Rubio has a 94 percent rating, while Sessions has an 81 percent rating. Rep. Steve King has a 77 percent rating. Gowdy himself has the same rating as Sessions — 81 percent.

Of the candidates running for president, only Sen. Ted Cruz has a higher rating on the Heritage scorecard, with a perfect 100 percent rating.

Other organizations, such as Conservative Review, have different ways of rating conservatives, but Heritage Action is among the most influential.