If you buy the conventional wisdom that Rudy Giuliani is too liberal on abortion, gun control, and gay rights to win the Republican nomination, you should want him in the Republican primary. Anything that forces John McCain to humiliate himself with more Stupid Politician Tricks is good for Democrats. Since Giuliani and McCain will be splitting whatever votes are available to Republicans Republicans don't trust, a Giuliani candidacy will put pressure on McCain, and push him into more electability-reducing panders to the GOP base. Unelectable Republicans like Gingrich and Brownback, who are more appealing to the base, have better chances of winning the primary if there's a strong Rudy candidacy that cuts into McCain's votes.
