During the 2010 elections, Crossroads GPS, the group co-founded by Karl Rove, spent millions and millions of dollars blanketing airwaves across the country with ads full of falsehoods and distortions that were widely debunked by independent fact checkers.

Now that’s happening again — only if anything, this time the distortions are even more brazen, and the sleaze factor is even higher.

Here’s the latest Crossroads ad, this one running in Massachusetts and hitting Elizabeth Warren for embracing Occupy Wall Street:

As I’ve been noting here, the right has responded to the protests by exploiting a cultural fault line that’s been key to our politics since the 1960s. Conservatives have elevated the protesters’ outsized tactics and violence to push the cultural buttons of blue collar whites and independents — who will be central to the Massachusetts race — in an effort to distract them from the populist message embodied by the protests and Warren’s candidacy.

The new Crossroads ad — which is backed up by a buy of nearly $600,000 — takes this to an almost comical level. It claims: “Fourteen million Americans out of work. But instead of focusing on jobs, Elizabeth Warren sides with extreme left protests.” Of course, Warren’s message, and that of the protests themselves, is all about jobs and unemployment.

This is the most transparent effort yet to use the protests’ theatrical extremes to divert the focus from their — and her — actual populist prescriptions, critique of inequality, and diagnosis of our financial crisis, which polls suggest blue collar whites actually agree with.

The ad then doubles down on this effort with an egregious distortion, claiming the protesters “support radical redistribution of wealth.” The ad’s source for that claim is that recent Doug Schoen Op ed that got so much attention for making that claim. But Schoen’s own numbers indicated that only four percent of the protesters he surveyed share that goal. The ad also falsely insinuates that Warren supports the violence we’ve seen, when she’s actually called on protesters to obey the law.

This latest effort follows another ad that Crossroads released yesterday, which is running in key swing states and is backed by a $2.3 million buy. The ad uses a snippet of a Bill Clinton interview, in which he seemed to oppose raising taxes, in order to argue that Clinton is at odds with Obama on how to address our fiscal travails. But as Steve Benen detailed in a must-read post, the idea that Clinton and Obama differ on taxes and spending cuts is just completely false.

Don’t take Steve’s or my word for it, though. American Crossroads recently ran a different ad in various markets using that same Clinton snippet, and Politifact flatly pronounced the use of Clinton to be “false.” And as a special bonus, that ad’s other core claim — that Obama’s position on taxes is “different” than it was in 2009 — was proclaimed to be untrue by FactCheck.org.

In other words, it’s happening again. When the outside ads really get going, there will be a great deal of media debate about the propriety of spending by these groups. But just as happened last time, virtually no one will focus on the actual content of the ads. Outside of a few fact checkers, few if any media types will care that the discourse is getting saturated by distortions and lies, or bother trying to determine which side is the worse offender in this regard.

UPDATE: Here’s the perfect response to the ad, in one sentence.