Forget Mitt Romney — the most serious flip-flopper in the race for the Republican Presidential nomination may just be Rudy Giuliani.

That's the case that is made in an extensive examination of Rudy's record in today's Boston Globe.

This must-read article is the best rundown we've seen yet on all the ways that this one-time national champion of socially liberal Republicanism has flip-flopped over to the right in order to please the Republican base.

On how many issues has Rudy flipped? Check out our rundown after the jump.

Here are the main points made by The Globe today:

• The latest flip flop is on gay marriage and civil unions, with an aide telling the Globe that Rudy opposes the civil union programs currently enacted in four states.

As recently as 2004, Rudy was saying, "So now you have a civil partnership, domestic partnership, civil union, whatever you want to call it, and that takes care of the imbalance, the discrimination, which we shouldn't have." However, Rudy now opposes civil unions, with a campaign aide saying Rudy was really talking about the benefits accorded by the more modest domestic partnership registry he created while mayor of New York City.

• Rudy used to speak out in favor of Roe v. Wade, but now says it "would be okay" if it were overturned, and has indicated he will appoint conservative judges.

• Rudy now supports the Hyde Amendment, which bars the use of federal funds for providing abortion. During his years in New York politics, however, he was a staunch critic of the Hyde Amendment, saying poor women needed to have access to abortions.

• Rudy previously opposed the ban on partial-birth abortion, publicly applauding Bill Clinton for vetoing. But he now supports the ban, and approved of the recent Supreme Court decision upholding it.

• On the subject of illegal immigrations, Rudy declared in 1994: "If you come here and you work hard and you happen to be in an undocumented status, you're one of the people who we want in this city. You're somebody that we want to protect, and we want you to get out from under what is often a life of being like a fugitive, which is really unfair." But Rudy came out this year against the recent failed immigration bill, saying there should not be any amnesty and supporting stricter methods of border controls, including mandatory identification cards.

• As mayor, Giuliani was a vocal proponent for Congress passing more gun-control laws, saying federal action was vital in helping states control gun crime. The Rudy of the year 2007, on the other hand, calls himself a "strict constructionist" on the issue, and says new gun laws should only be passed at the state level.