The public discourse would be better off if more television stations pulled political attack ads that mislead the public.

An ad by Karl Rove-backed Crossroads GPS was yanked from rotation on a Montana cable show because it made claims that the network deemed false. Recently a number of ads by the well-funded conservative outfit have been declared misleading and false, but the spot targeting Sen. Jon Tester (D-Mont.) is apparently the first pulled from the air. The Associated Press reported that other outlets are still running the ad. In it, Tester is accused of supporting an Environmental Protection Agency rule — a rule that was never in fact proposed — to regulate farm dust. But the vote that the ad cites actually had nothing to do with dust or the EPA; it was a procedural vote on a measure aimed at cracking down on China for manipulating currency.

Rove’s attack operation, in other words, put together yet another blatantly dishonest attack ad. Kudos to Cablevision’s Optimum cable service for dropping the spot.

Keep in mind, of course, that this latest example fits nicely into the larger pattern of dishonesty emanating from Crossroads GPS. Rove’s outfit was caught blatantly lying earlier this week in an ad that argues former President Bill Clinton disagrees with President Obama on tax policy (the opposite is true). Crossroads GPS was then caught pushing obviously bogus claims to smear Senate candidate Elizabeth Warren in Massachusetts.

Two days later, Rove’s operation was also caught making demonstrably false claims about former Gov. Tim Kaine (D), running in a very competitive U.S. Senate race in Virginia.

And now a Montana network is pulling a fourth ad from Crossroads GPS because it makes claims that just aren’t true.

I’m starting to get the sense that Rove’s attack group has an honesty problem.

As Greg Sargent noted yesterday, “At risk of sounding terribly earnest, I’m going to continue to insist that it kind of matters that Crossroads GPS … is again blanketing airwaves across the country with millions of dollars in ads containing demonstrable falsehoods and distortions.”

Agreed. When one attack operation releases four ads in a week, and all four are proven to include obvious falsehoods, it’s not unreasonable to think Crossroads GPS is less an “advocacy organization” and more a group of professional liars.