Good old Mitt Romney, he goes out to Iowa and tries to ingratiate himself with the denizens of the red belt by referring to the "Big Dig" as "The Tar Baby".
For anyone who doesn't know, the term "tar baby" means "a situation or problem from which it is virtually impossible to disentangle oneself". To many it has a derogatory connotation, those reasons are explained here.
And when I went looking for the particular quote in the speech on Boston.com, the following ad pops up:
Now that is just unfortunate.
As to the quote that is causing a brouhaha (can I still use that term?), here it is:
"The best thing for me to do politically is stay away from the Big Dig -- just get as far away from that tar baby as I possibly can"