The problem is that claim isn’t supported by facts, as even the Washington Post was forced to admit:

There are two key problems with the president’s use of this statistic: The numbers are about two decades old, yet he acts as if they are fresh, and he refers to “purchases” or “sales” when in fact the original report concerned “gun acquisitions” and “transactions.”  Those are much broader categories of data.

As we noted before, the White House said the figure comes from a 1997 Institute of Justice report, written by Philip Cook of Duke University and Jens Ludwig of the University of Chicago.

This study was based on data collected from a survey in 1994, the same year that the Brady Act requirements for background checks came into effect. In fact, the questions concerned purchases in 1993 and 1994, and the Brady Act went into effect in early 1994 — meaning that some, if not many, of the guns were bought in a pre-Brady environment.

Digging deeper, we found that the survey sample was just 251 people. (The survey was done by telephone, using a random-digit-dial method, with a response rate of 50 percent.) With this sample size, the 95 percent confidence interval will be plus or minus six percentage points.

The Police Foundation report did not break out gun purchases, so in January we asked Ludwig to rerun the data, just looking at guns purchased in the secondary market. The result, depending on the definition, was 14 percent to 22 percent. That’s at least half the percentage repeatedly cited by Obama. (In a recent article for National Review, Cook and Ludwig wrote “we don’t know the current percentage — nor does anyone else.” But they say if the percentage is lower it actually strengthens the case for expanding background checks because it would be less expensive to implement.) Since our initial report on this statistic appeared, The Washington Post in February included a question on background checks on a survey of Maryland residents, asking whether they went through a background check during a gun purchase in the past 10 years. The result? Twenty-one percent say they did not.

Coincidentally or not, 21 percent falls within the 14-to-22 percent range for gun purchases without background checks in the 1994 survey.

Obama is making his claim using a statistically insignificant sample size, with data nearly 20 years old, collected under a different set of laws than those we’ve been operating under since Brady made NICS background checks the law of the land. It is irrelevant, invalid data, intentionally misrepresented as being current and relevant.

In short, the president has been caught in yet another lie attempting to support controversial firearms legislation that he would like to see passed. Barack Obama demanded a “national conversation” about gun control.

Then he filled it with lies.