Race ratings: Murkowski write-in shifts landscape in Alaska

Between the surprise primary win for Tea Party-backed Joe Miller and the decision of Sen. Lisa Murkowski (R-Alaska) to launch a write-in bid, there's a new level of uncertainty in Alaska's Senate race.

What was once a safe seat for the GOP has undoubtedly received a new jolt of competitiveness ahead of the fall. As a result, we're moving the race out of the "safe Republican" category and shifting it to "lean Republican."

The fear among Republicans is that Murkowski's write-in bid could split the Republican vote between her and Miller and create a possible path to victory for Sitka Mayor Scott McAdams (D). Murkowski is working to appeal to centrists--labeling Miller "extremist" and McAdams a lightweight with an inability to bring home the bacon for the state.

The national party remains confident in Miller, however, and a GOP source points to internal polling that indicates Murkowski's write-in bid takes an equal amount of support from Democrat Scott McAdams as it does Miller. 

The greatest complication for prognosticators is how to poll what has become a three-way race. Alaska-based pollster Marc Hellenthal says Murkowski's write-in bid means there will likely be a large drop-off between those who express their support for the incumbent in polls and the actual level of support her bid garners on Election Day, but determining just how large that drop-off might be is nothing more than guesswork.

On Friday, Murkowski declared that Alaksa "cannot accept the extremist views of Joe Miller," and warned Miller and the Tea Party Express that "the gloves are off."

See the Ballot Box's complete race ratings here.