The 10th Amendment got left off the bus again. (Tim Dominick/The State/MCT)

Seems Rick Perry would prefer just to eat it.

On Friday, he signed the National Organization for Marriage’s pledge opposing gay marriage.

Remember when Rick Perry said that New York’s legalization of gay marriage was “fine with me”? You should. It was just a few weeks ago — July 22, in fact.

“Ah, but if I’d known then what I know now,” Perry says. “What I didn’t know then was that I was the Republican front-runner.”

Amazing the difference a bit of knowledge can make.

“That’s New York, and that’s their business, and that's fine with me. That is their call. If you believe in the 10th Amendment, stay out of their business.” That was then, before Rick Perry learned different. He has been doing a lot of learning in recent days, shedding ideas from his book (published in 2010) right and left (mainly left) and outdated opinions (four weeks ago, he was a different man!) at the drop of a poll.

Perry believes in the 10th Amendment, but, well — you have to draw the line somewhere. And, as I suggested before, that line is “when other states do things we frown on in Texas.”

The 10th Amendment is the one that tends to be ditched at the altar these days.

“I believe in you!” candidates insist. “You’re swell. You’re not the 10th Amendment in my heart. More like the First Amendment!”

The 10th Amendment smiles and blushes, and then it gets word of something like this. When it shows up at a bar to hang out with the 21st Amendment, the 16th Amendment is the only one willing to have anything to do with it.

“Everyone needs us,” Sixteen grouses. “But nobody loves us.”

They sigh and clink their glasses together.

“Second Amendment doesn’t even come here any more,” Twenty-First Amendment sighs. “She’s too cool for us now. Keeps going to rallies.”

“First Amendment left years ago to hang out with the ACLU.”

“I’m still here,” says the Third Amendment.

Everyone shudders. “No one was talking to you.”

“No one ever is,” Third Amendment says sadly. “You guys want to stay at my place this weekend? You can bring British troops, if you want!”

“You know we can’t do that,” Twenty-First says.

Poor 10th Amendment frowns. “This’ll be me someday,” it thinks. At the rate things are going, it might be right.

But maybe Rick Perry will have learned something different next week.