Mitt Romney has attacked President Obama's new immigration policy as an election-year ploy that fails to provide a long-term, comprehensive solution to our broken immigration system. It's not the first time that Republicans have made the argument: Four years ago, Sen. John McCain made the same argument, pointing to Obama's record in the Senate.

(Associated Press)

The charge is that then-Senator Obama jettisoned the 2007 push on comprehensive immigration reform by insisting on partisan, poison-bill amendments that doomed the legislation's chances in the Senate. In July 2008, John McCain accused him of having "voted for and even sponsored amendments that were intended to kill the [immigration overhaul] legislation." Later, he singled out Obama's support for an amendment "that basically gutted the legal temporary worker problem," allying himself with organized labor interests.

But what really happened four years ago? Politifact delved into the question a few years ago: In June 2007, then-Senator Obama did, in fact, offer an amendment to the legislation at a time when supporters warned "it could be derailed by any amendments that changed its substance," Politifact writes. Obama's amendment wasn't, in fact, focused on the temporary worker provisions; instead, he wanted to put an expiration date on a new, "merit-based" system "that apportioned green cards based on the nation's economic needs and moved away from the existing system, which rewards family ties," the piece explains.

Obama's amendment was defeated. But there is some truth to McCain's argument: Obama subsequently supported an amendment from then-Sen. Byron Dorgan to phase out a new program to increase the number of temporary workers, which labor unions opposed. Politifact explains what happened next:

Supporters of reform warned that the amendment could scuttle the deal, but the Senate adopted the amendment in a 49-48 vote, with Obama voting with Dorgan. The bill's supporters branded Dorgan's effort a "deal-breaker."

Subsequent to that vote, the legislation failed to overcome a Senate filibuster. And Obama was among those voting to break that filibuster.

So Obama didn't single-handedly doom comprehensive immigration reform as a senator, any more than he's single-handedly blocked a long-term solution from happening as president.

One thing does stand out about his immigration record in the Senate, however: His amendment opposed an effort to prioritize a more meritocratic immigration system to bolster the country's economy. Now, he's aggressively pushed through a policy change that would do precisely that — reward "the best and brightest" young immigrants before everyone else.