Two conservative groups released their annual scorecards on Monday. On both, Republicans running for reelection became more conservative in 2013 than their peers.

Club for Growth and Heritage Action issued the scorecards, which document the willingness of members of Congress to support the groups' conservative priorities. The names most willing to vote along a strong conservative line won't surprise you: Sens. Ted Cruz and Mike Lee. Nor, probably, will that other bit of data: that Republicans running for reelection became more conservative than Republicans at large.

For the most part, the scorecards don't do a lot but measure Republican orthodoxy. Politico notes that two Democratic House members got decent scores — of 40 percent, meaning they voted the way the groups wanted less than half the time. Otherwise, the top scores are all Republicans.

Club for Growth Heritage Action

Senate

  • Ted Cruz, Texas, 100%
  • Mike Lee, Utah, 100%
  • Rand Paul, Kentucky, 97%

Senate

  • Ted Cruz, Texas, 100%
  • Mike Lee, Utah, 100%
  • Rand Paul, Kentucky, 96%

House

  • Trent Franks, Arizona, 100%
  • Tom McClintock, California, 100%
  • Matt Salmon, Arizona, 100%
  • David Schweikert, Arizona, 100%

House

  • Trent Franks, Arizona, 100%
  • David Schweikert, Arizona, 100%
  • Matt Salmon, Arizona, 97%

Strong showing by the Sun Belt.

What's more interesting, though, is to compare this year's rankings with previous rankings. I pulled data on the most recent rankings from each group prior to that released on Monday — Club for Growth's 2012 and Heritage Action's ranking from the previous Congress.

Overall, Republican senators got, on average, 3.24 percent more likely to vote with Club for Growth between 2012 and 2013. That could be a function of a lot of things, including the organization changing the sort of things it scored or a shift in the partisanship of the body, for example. For Heritage Action, Republican senators were 5.5 percent less likely to vote with the group.

But when you look at just those 13 Republican senators who are up for reelection, on both scorecards they grew substantially more conservative.

Republicans facing primaries from other Republicans were 6 percentage points more supportive of Club for Growth priorities and about 5 percent more supportive of Heritage Action's. And that's including South Carolina Sen. Lindsey Graham, whose scores dropped last year. Taking him out of the mix, it's more stark: Republicans facing primaries jumped 11.83 percent on Club for Growth's rankings and also became more conservative — by a tiny margin — on Heritage Action's.

Which is why the groups score votes, of course. Their explicit goal is to provide a metric by which voters can measure elected officials. Whether or not the voters pay attention to it, the senators clearly do.