Politicians and Harry Potter?

In a recent interview Barack Obama was asked who is favorite Harry Potter character was, to which he replied “Dumbledore’s a very cool guy.” He then skipped over the whole purple robes and high heeled boots thing (“Well, he’s gay, apparently.” Obama: ”[laughs] No comment on that.”), but it got me thinking; Who is Barack most like in the book? And that got me thinking, what other politicians resemble Harry Potter characters?

Also, are there any that she actually based off British politicians?

Some ideas: Gilderoy Lockhart? Minerva McGonagall? Aberforth Dumbledore? Crouch, Fudge, Scrimgeour and Umbridge?