Scott Brown's 'candidacy would almost certainly force Democrats to wage another highly competitive race in a year when they are fighting to keep control of the Senate...'

The quote's from the great write-up, at the New York Times, "Scott Brown Moves One Step Closer to a Senate Bid":

Mr. Brown came to national attention with his upset win in 2010 for the Senate seat in Massachusetts long held by Edward M. Kennedy. He was a senator for only three years before he was knocked out by Ms. Warren in a slugfest that became the most expensive congressional race in the country.

But it was clear he loved the limelight. On the night he lost to Ms. Warren, he told supporters that “defeat was only temporary,” a signal that he would be running for office again someday. And last April, he hinted broadly that he was looking at the Senate race here.

Since then, he has taken all the evolutionary steps necessary for his announcement on Friday, including selling his home in Massachusetts and moving full time into the second home that he has owned in New Hampshire for two decades. (The Constitution requires only that senators live in the state at the time of the election.)

In an impassioned announcement speech that dwelled on his family’s longtime connections to New Hampshire, Mr. Brown also warned, “A big political wave is about to break in America, and the Obamacare Democrats are on the wrong side of that wave.”

If he were to win in November, Mr. Brown would join an exclusive club: senators who represented more than one state. There have been two, both in the 19th century. The record-holder is James Shields, who represented Illinois, Minnesota and Missouri. Waitman T. Willey went to the Senate from Virginia and later West Virginia.

Former Senator Bob Smith has already announced his bid to win back his old seat (he represented New Hampshire in the Senate from 1990 to 2002). So, we'll see how far Brown's celebrity carries him in what appears to be a highly competitive GOP primary.

RTWT at that top link.