In my opinion the weakest point is the same as the strongest point: Bush and Rove.
So far Rove has gotten most of it right, and he certainly did a masterly job this year. But he still doesn't seem to get one basic, fundamental political point: the Republicans can't win unless they have the support of the right-to-lifers. And he has too often convinced Bush to go along with him against his own principles.
Rove failed to back Schundler in New Jersey last year because he let the party hacks there convince him that a pro-lifer couldn't win. Rove failed to back Simon this year (after a few weeks' half-hearted effort) because he let the RINOs in California convince him of the same thing. For that reason he left a RINO loser in charge of the state party, who undermined the candidate.
Let's put aside the moral aspects of the pro-life position for a minute and consider the political reality. The Repulican pros seem to think they can constantly abuse and disappoint the pro-lifers and the conservative religious elements of the party and get away with it, because these people have nowhere else to go. But they can stay home, and they often have stayed home when they are given no choice to voite for or when they expect the Republicans to betray them once again, as they have so often in the past. It was their enthusiastic participation in the last election that turned the tide in most races.
This last election was a big win for the pro-lifers, and a big defeat for Emily's List. Rove had better realize that and do something practical to convince the RNC and the pros what the position is. Otherwise, this golden opportunity will be frittered away as it has been so often in the past.