LET’S TALK ABOUT PREMIUMS…. The White House’s summit is about a third complete — the first two hours felt like 20 — but there’s one point of contention that’s come up repeatedly, so it’s worth setting the record straight.

Sen. Lamar Alexander (R-Tenn.) argued, in the Republicans’ opening statement, that the CBO found that health care premiums would go up under the Senate Dems’ reform plan. President Obama insisted that this wasn’t true, and after some back and forth, concluded, “I’m pretty certain that I’m not wrong.”

And, he’s not wrong at all. Alexander just doesn’t understand the issue very well.

Lamar Alexander and Barack Obama just had a contentious exchange on this point, so it’s worth settling the issue: Yes, the CBO found health-care reform would reduce premiums. The issue gets confused because it also found that access to subsidies would encourage people to buy more comprehensive insurance, which would mean that the value of their insurance would be higher after reform than before it. But that’s not the same as insurance becoming more expensive: The fact that I could buy a nicer car after getting a better job suggests that cars are becoming pricier. The bottom line is that if you’re comparing two plans that are exactly the same, costs go down after reform.

You can find a full rundown of the report here.

Let’s not forget, though, that the president explained this quite well, and yet, at least three other Republicans — so far — have said the Democratic plan would raise premiums.

Now, it’s possible that these GOP lawmakers aren’t paying attention. Maybe they’re lying and hoping we won’t know the difference. Perhaps they came with memorized talking points, and weren’t able to adapt after reality had been explained.

But it’s nevertheless a reminder about why policy discussions with Republicans tend to be pointless. They make claims that aren’t true, and after being corrected, repeat those claims again anyway.

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.