Mitt Romney dropped a negative ad in New Hampshire attacking John McCain. However, it seems that Romney, again, has some truthiness problems. Given the factual errors below, it is clear why McCain goes straight to Romney’s credibility problem.
Factcheck.org, "More Mitt Malarky":
Romney’s latest ad attacks McCain in New Hampshire with false and misleading claims
Mitt Romney, who targeted Mike Huckabee in an earlier commercial, is now running the most negative campaign of any presidential candidate in either party. … Romney’s description of McCain’s failed immigration bill — which was backed by President Bush — is so selective as to be misleading.
Specifically, Mr. Romney assails Mr. McCain on both tax policies and immigration. On both topics, the commercial presents facts that could be construed either as selective or worse, misleading.
First negative ad against Romney by any candidate, first negative ad by McCain, first negative ad by any candidate besides Romney.
Negative campaigning. Lying. Debating what the definition of "saw" is. Who does that sound like?