Despite admitting that his immigration stance was a major factor contributing to his declining polling numbers last spring, John McCain is attacking Mitt Romney on that very issue in a mailer being sent out to New Hampshire residents.

In a piece titled, “Why is Mitt Romney attacking John McCain? To hide another flip,” the Arizona Senator features a number of Romney immigration quotes through the years which he says shows “totally inconsistent policy positions.”

Among the quotes he uses in a section called “Mitt’s Mixed Message on Immigration,” is a March 2007 quote of him saying “I don’t believe we’re going to round up the 12 or 20 million people and deport them,” juxtaposed with a May 2007 statement, “I am going to tell them to go home.” (See more of mailer after jump)

New Hampshire Republican Chairman Fergus Cullen, says the new McCain and Romney pieces are among the most critical mails he has seen go out to NH residents thus far.

“Direct mail often falls below the radar screen,” he said, but adds that “the race is only going to heat up in New Hampshire mail boxes in the coming weeks.”

The mailer goes on to add, “That’s why voters don’t trust Mitt Romney. No wonder Mitt Romney is trying to cover up his own mixed-up record by smearing straight talker, John McCain.”

**** UPDATE****

Response from Jim Merrill, Romney for President New Hampshire State Director:

“Senator McCain’s weak approach to illegal immigration should be the last issue that he tries to use when attacking and distorting the strong record of Governor Romney. This low-road negative attack by Senator McCain directly contradicts their claim that he would never go negative. The decision to mask a record on illegal immigration that puts John McCain at odds with Republican voters with a negative hit on the governor shows that the ’straight talk’ era is long gone and has been replaced by routine desperation politics.”

***UPDATE 2**

It turns out that as late as last week, McCain’s National Political Director Mike Dennehy said the campaign wouldn’t go negative, telling the Manchester Union Leader, “no matter how tough it gets, McCain won’t go negative, says national political director Mike Dennehy. He said, in fact, that the campaign is considering formally urging the other campaigns not to air attack ads.”