HSR LIE JUST WON’T GO AWAY…. Once a claim makes its way onto the approved list of Official Republican Talking Points, it’s there to stay. Even after a claim has been exposed as completely false — sometimes, especially after it’s been proven false — GOP figures will just keep repeating it.

When it comes to the stimulus package, we have a few too many examples to choose from. The marsh-mouse preservation spending is obviously a good one, but the notion of Harry Reid securing an $8 billion earmark for high-speed rail between Los Angeles and Las Vegas is a genuine Republican classic.

Here’s reality: as negotiations on the package wrapped up, Rahm Emanuel secured an extra $8 billion for high-speed rail. The Maine and Pennsylvania Republican “centrists” approved, and the bill progressed. The $8 billion is not directed at any specific state or project.

Regardless, conservatives quickly began arguing that the $8 billion was Reid’s idea, and would go exclusively to connect Los Angeles and Las Vegas with HSR. “Tell me how spending $8 billion,” House Minority Leader John Boehner asked, “in this bill to have a high-speed rail line between Los Angeles and Las Vegas is going to help the construction worker in my district.” The argument doesn’t really make any sense — not every infrastructure bill is going to benefit every worker in every district — but more importantly, the $8 billion earmark doesn’t exist in reality.

And yet Boehner and his cohorts kept repeating the lie, and now it won’t go away. Here’s John McCain today:

“So, we will be seeking fair and transparent use of the money. I believe that Arizona can compete with any other state or locality to get the much-needed money. Already we’re seeing a good example. There was $2 billion in the Senate bill of the stimulus package for light rail; there was zero in the House. It came out of conference — only Democrats, no Republicans in the room – with $8 billion for light rail. And guess where it’s going to go? A light rail between Las Vegas and L.A. Everybody knows that.

“Could we have competed for that money? Maybe so. So it’s business as usual in Washington, and I think that Americans are generally very disappointed. Sorry for the long answer.”

He should be “sorry,” but the problem isn’t the length of the answer, it’s the blatant dishonesty of his answer.

It’s certainly possible that McCain just doesn’t know what he’s talking about. Maybe he saw someone repeat the lie on Fox News, and assumed it was true. McCain has never been especially detail-oriented, which is why he manages to make patently false claims with some regularity.

But this one is especially egregious, and not just because there is no $8 billion for light rail between L.A. and Vegas. As Matt Yglesias explained, “The thing that John McCain wants where different states can compete for the high-speed rail money is what the bill already says. Except McCain has piled ignorance onto dishonesty by confusing high-speed rail (advanced passenger trains that run between cities) with light-rail (relatively low-capacity trains used for intra-city mass transit).”

So, in this case, McCain is not only lying, he’s confused about the subject on which he’s lying. He then insists, “Everybody knows that,” as if those who accept reality are somehow ignorant.

It’s a helpful reminder of why policy debates with congressional Republicans don’t usually go well.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.