Most people aren't shallow enough to vote the way their "union" or AARP tells them to. They generally have more than one issue. A terror attack in the states would almost cinch a Repub win in November. The Dems would scream, "You see, we still aren't safe!", but they have no alternative other than to cut and run or negotiate with throat cutters.
...no, they'll scream that the attack was planned and executed by Rove and company - to affect the outcome of the election...
*big smile*