He flipped. That makes him a public liar, since earlier in the day "Romney further explained his vote in a pre-taped interview with Fox News, in which he explicitly said he believes the president should be removed from office." and the speech itself "... my own reasoned judgement convince me that a president can indeed commit acts against the public trust that are so egregious that while they are not statutory crimes, they would demand removal from office". Why he flipped  like light switch right before the vote on the 2nd Article is very odd.