President Obama at the United Nations on Tuesday, Sept. 25 (Seth Wenig/AP)

Take, for example, The Washington Post’s op-ed columnist Marc Thiessen’s Sept. 10 piece saying President Obama has failed to attend his daily intelligence briefing (or PDB) “more than half the time.”

Thiessen’s column was based on numbers from the Government Accountability Institute, which he described as a “new conservative investigative research organization.” (It’s now being called a “nonpartisan” research group.)

GAI was founded by Peter Schweizer, an author who consulted for the Bush II White House speechwriting operation. (Thiessen and Schweizer also founded a business called Oval Office Writers in 2009.)

Schweizer, the only person listed on the GAI Web site as being on the GAI “team”, used Politico’s White House calendar — as opposed to the skimpy, official White House schedule — to calculate Obama’s daily intelligence briefing attendance.

Our colleague, Washington Post Fact-Checker Glenn Kessler, debunked the GAI analysis as meaningless, given that different presidents have different ways of getting briefed on intelligence matters — some prefer just to read the Presidential Daily Brief, some prefer just meeting with their national security adviser and so on. He gave it three Pinocchios (of a possible four). Thiessen disagrees.

But then Karl Rove’s Operation Crossroads super PAC picked up on the analysis when it blistered Obama in an ad for his supposed intattentiveness to foreign policy and cited The Washington Post column.

Next thing you know, as Kessler pointed out to us, the White House Calendar, starting Sept. 14 (four days after Thiessen’s column) and for every workday last week and up to Monday, says that Obama — and sometimes, Vice President Biden — is briefed.

Asked about that recent uptick in Obama’s “attendance, ” White House spokesman Tommy Vietor said Tuesday afternoon that, “As we’ve said countless times, the President reads the PDB every day and most days he’s in D.C. has an Oval [Office] session. That scheduling has nothing to do” with Thiessen’s column.

Well, okay.