Scales Tip in Brown's Favor?

Politico reports Charlie Cook thinks the Massachusetts Senate race slightly favors Brown though it still could go either way:

"This past Thursday, Jan. 14, The Cook Political Report moved the open Massachusetts Senate seat rating from lean Democrat to toss-up, having moved it from solid Democrat to lean Democratic on Jan. 7," Cook wrote. "We continue to see this race as very much of a toss-up, with Republican state Sen. Scott Brown holding onto a very narrow, single-digit lead over Democratic state Attorney General Martha Coakley.

"Given the vagaries of voter turnout, particularly in lower participation level special elections, this race could still go either way, but we put a finger on the scale for Brown. Last-minute Democratic attacks on Brown have driven his negatives up some and slightly diminished the incredible intensity of support that Brown enjoyed, but it looks more likely than not to hold."

 Ed Morrissey notes the polls have settled yet runs the numbers based on several different turnout models.  Under the best case scenario for Dems, Brown still leads by 4.5 points.

Update II: Reader S averaged the exit-polling data from the 2006 and 2008 races — in which Dems were highly motivated and independents tilted against the GOP — and came up with a 41-18-41 split.   In that best-case turnout model, Brown leads by 4.5 points using the ARG survey responses:

2006-8 Average Model			Brown	Coakley
Dems	246		49.2	174.66
GOP	108		101.52	1.08
Indys	246		142.68	91.02
			293.4	266.76
			48.90%	44.46%

That’s high-end best-case for Coakley, and she’s still losing.

 The POTUS is about to speak in Massachusetts, can he reverse the tide?  It's all about turnout but an interesting note Fox reported the hall for the POTUS/Coakley event is not full.  Still way too early for champagne though.