Because he's going to be held in check by certain political realities that we should all be aware of. And because, as I have said, electing Romney isn't just electing Romney. There is an entire "establishment in waiting" that will come in with Romney, and lots of its members are going to be working behind the scenes to advance our causes.If Liberal Romney is elected President he will be the top Republican and no doubt supporting RINO candidates for elected office. If you allow him that power for the next 4 election cycles as President and possibly thereafter, then Romney is worse than Obama. The democrats will be promoting Libs on their side and Romney would be promoting Libs (like himself) on our side.
If you really believe Republicans are going to keep Romney in-check (Ha-ha-ha!), then just look back at recent history of the over spending the Republicans engaged in when they held power under Bush. Expecting that the GOP will pressure Romney to be a decent human being is not realistic. In fact, Romney will be in a prime position to make the Republican party worse by supporting RINO candidates for years to come.
Down ticket elections are about rallying the true believers. You really think Romney will do that? Please.
At worst Romney will be a non factor, versus Obama the ideologue who will inspire liberals to vote for dog catcher.
So even within the context of your silly argument it still makes more sense to go for Romney.