Last week, Republicans pushed back against claims that congressional challenger Keith Rothfus had business links with China. Today, Democrats seemed to back down. They removed the reference from a new version of their television ad.

The Democratic Congressional Campaign Committee’s latest version of the commercial omits a line about Rothfus’s former employer – but keeps the focus on trade policy. Rothfus, an attorney from Allegheny County, faces Rep. Mark Critz (D-Cambria) in Pennsylvania’s top congressional race of 2012.

“Keith Rothfus said, quote, ‘I believe in free trade’,” an announcer says in the newer ad.

In the original version, the same announcer said, “Keith Rothfus worked for a law firm that had a ‘strategic alliance’ with a Chinese firm.”

In both versions, the speaker continues, “Maybe that’s why he signed a pledge that protects tax breaks for companies that ship jobs overseas.” The conclusion of both ads is the same.

Republicans quickly criticized the first version of the ad, calling the basis for the claim absurd. Rothfus worked as a junior associate at a law firm in 1993, but left just a few weeks after the firm partnered with another law firm in China.

Rothfus Campaign Manager Jon Raso contends that the switch was a retreat by Democrats.

“This proves Keith Rothfus was right, the attacks against him are so blatantly false even they had to admit it and change the ad,” said Raso. “Now if only they admitted it’s been the policies of President Obama and Congressman Critz that have sent our jobs overseas they’d actually have an honest commercial.”

The DCCC says the change is part of an evolving ad campaign, not a retraction, and that Rothfus’s support for free trade is more damaging than the China link. The committee is on the air as an independent expenditure, and so cannot by law coordinate with Critz.

Rothfus’s campaign aired its own commercial in response to the DCCC’s ad. The effective spot includes a blurry screenshot of the law firm claim from the DCCC’s original ad.

“The attacks are wrong. The closest Keith Rothfus has been with China is when he’s ordered takeout for his family,” says the Rothfus ad announcer, incredulously.

Here’s the new DCCC ad:

And here’s the original one: