Brown by four with four days to go...

New polling data:

GOP upstart Scott Brown is leading in the U.S. Senate race, raising the odds of a historic upset that would reverberate all the way to the White House, a new poll shows.

Although Brown’s 4-point lead over Democrat Martha Coakley is within the Suffolk University/7News survey’s margin of error, the underdog’s position at the top of the results stunned even pollster David Paleologos.

“It’s a Brown-out,” said Paleologos, director of Suffolk’s Political Research Center. “It’s a massive change in the political landscape.”

There are still four days to go, and the machine has been threatened and backed into a corner. The Democrats, despite their exceptionally lousy candidate, still have enormous structural advantages. But it's starting to look as if it could actually happen...