Sen. Rand Paul (Melina Mara/The Washington Post)

Sen. Rand Paul (R-Ky.) has a problem with the truth. It is not that he intends to mislead or fabricate; rather he has very few facts at his fingertips and no competent staff willing or able to fill in the blanks.

This leads him into serial falsehoods, whether it is on the Fourth Amendment, “neocons,” President Dwight D. Eisenhower or the Cold War. The latest is more than a tad embarrassing for a libertarian and son of Federal Reserve-basher and former Texas congressman Ron Paul.

Jim Pethokoukis has the goods:

First, Rand Paul told Bloomberg BusinessWeek that he would prefer a deceased Milton Friedman in charge of the Federal Reserve “because then you probably wouldn’t have much of a functioning Federal Reserve.” Now as a follow-up, he writes over at National Review Online that it “is a disservice to Milton Friedman’s memory … to assert that he would be a Krugman-like advocate for quantitative easing.”

Based on the BBW interview and his NRO piece, Paul doesn’t seem to know or understand much about Milton Friedman’s views on the Fed or monetary policy. The NRO piece is particularly egregious since Paul and his staff had time to research the issue and still failed to mention that Friedman had addressed specifically what a central bank should do when faced with a stagnant economy and very low interest rates.

He then proceeds to document Friedman’s long and public record on the Fed. In particular he documents Friedman’s support for the precise tactic employed by Fed chairman Ben Bernanke. (“They can buy long-term government securities, and they can keep buying them and providing high-powered money until the high powered money starts getting the economy in an expansion.”)

This is no small error. Friedman is the king of monetarism; to assert the opposite highlights Paul’s significant ignorance on a subject that should be in his bailiwick.

Paul could certainly educate himself. He could hire knowledgeable staff. But he seems to have no interest in doing so. He prefers instead to hopscotch from one black-and-white ideological touchstone to another. His world view is so narrow or entirely lacking that he assumes (or convinces himself) the facts line up with his extremism.

In the Senate, this is not an impediment to success. Many senators blather nonsense with little regard for the facts. Senators aren’t responsible for much other running their own office (which Rand Paul does abysmally, as we found out from the “Southern Avenger” hire). But someone aspiring for a national profile and a presidential campaign isn’t going to get away with this. Interviewers, opponents and the media will catch him — again and again. That is how Herman Cain and Al Gore became laughingstocks — they repeatedly said things that just weren’t true. Cain didn’t know much about anything.

Running for president is harder than it seems. Ask Texas Gov. Rick Perry. It’s even harder when you are, to be blunt, an ignoramus.

Jennifer Rubin writes the Right Turn blog for The Post, offering reported opinion from a conservative perspective.