Don't get me wrong, I see the appeal of nailing down George HW Bush's endorsement. It signals to the GOP establishment and the media that the nomination is effectively over, probably helps Romney raise some money, and maybe gets a few more fence-sitting Republican elites on board. Still, I'm not entirely sure that outweighs the negatives in Romney's case. After all, Romney is doing fine in the GHW Bush wing of the Republican Party. Where he's struggling is the portion of the party that sees Bush as a sellout, and which worries Romney is made of similar stuff.
Now, as a practical matter, the effect is pretty marginal either way, so I don't see much downside risk. On the other hand, the one sure way for Romney to keep the primaries going a few more months is by losing Wisconsin, and I'd guess Bush hurts a bit more than he helps in that regard. (The latest poll has Romney up 39-31 there, so it's not quite in the bag.) Why not wait a week on this?
Update: Actually, there's a new NBC/Marist poll out today showing Romney up only 7. As I say, Santorum's still a long-shot--as the poll notes, Wisconsin's demographics look more like the states Romney's won than the states he's lost. But no need to tempt fate with victory less than assured.
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