Politics, as you may have noticed, can be somewhat fungible.

You know, in the sense that representing a blue-to-purple state such as Pennsylvania can require some wiggle room when it comes to hard-line issues.

That said, I couldn't help but notice a slight wiggle evident in ratings of Democratic Sen. Bob Casey and Republican Sen. Pat Toomey that are awarded annually by the Club for Growth, a national conservative powerhouse with lots of money and clout.

The club ranks members of Congress on the basis of votes on free-market issues, rewarding like-thinkers with high marks and slapping low grades on tax-and-spend, big-government types.

Its ratings for 2014 were released Monday.

And it's no surprise Toomey drew a rating of 86 percent and a ranking of 14th among the Senate's 100 members.

Neither is it a stunner that Casey's rating is 20 percent, placing him right around the middle with a ranking of 47th.

But here's the thing: both Senators moved a bit since taking office.

Toomey, a former president of the club (from 2005 to 2009 after serving a stint in the House) got a rating of 97 percent during his first year in the Senate (2011), which placed him 9th among 100.

And Casey, in his first year (2007) got a rating of zero percent, tied with some other Senators for 97th place.

Oh, and others sharing that level back in 2007 included then-Sens. Hillary Clinton and Barack Obama.

So Toomey, who faces reelection next year, has actually moved down the club's ladder by 11 percent. And Casey climbed up by 20 percent.

Not to worry, though, the club endorses Toomey's reelection. And Casey has until 2018 to maybe move up a little bit more.

Nice to know rigidity can soften -- over time.