The Obama campaign tries to do so regarding Mitt's latest auto-industry claims:

They're also touting Colin Powell's endorsement in a new nine-state radio ad. Meanwhile, the Romney campaign is deploying Nevada Governor Brian Sandoval:

The two presidential campaigns have already spent a combined $45 million for the final week, and there is more to come. Zooming out, the Center For Responsive Politics says 2012 campaign spending will surpass $6 billion, with $2.6 billion of that total coming from the presidential campaign. In outside spending news, pro-Obama Super PAC Priorities USA is up with a Florida ad that tries to connect Romney to Republican Governor Rick Scott:

Cameron Joseph explains why the Super PAC is tying the two men together:

Scott eked out a victory in 2010 despite attacks on his business dealings on Medicare both during the primary and general election, and is one of America's least popular governors — a late September poll had his approval rating at 38 percent, marking an improvement from earlier polling.

The group Planned Parenthood Votes is writing out the difference between Romney and Obama in this new spot:

On the other side of the trail, pro-Romney Super PAC Restore Our Future is spending $1.1 million in Minnesota and $700K in New Mexico – more late expansion of their originally-targeted territory. The (previously seen) ads are here and here. Alexander Burns notes:

[With ads now running in NM, PA, MN and MI,] Republicans are finally competing for the electoral votes of all the states George W. Bush sought to win in 2004. There's a limited amount this kind of spending can do, in the absence of field operations and the candidate's presence, especially this late in the race. We'll see if Democrats move to counter the buy in New Mexico, as they have in the other states.

The Koch dark-money group Americans For Prosperity is throwing its weight behind Romney in Michigan and Pennsylvania with two AFP reruns from earlier in the year ($3 million buy, watch them here and here), while another dark-money group, American Future Fund, is out with pro-Romney ads in Iowa and Florida. In wing-nut news, an anti-Obama mailer in Iowa makes a debunked claim that Obama doesn't think America is a "Christian nation." By the way, the people behind those voter fraud billboards in the Midwest were exposed. On the down-ticket, Romney will appear in an ad supporting Montana Republican Denny Rehberg's Senate campaign, while in Massachusetts, Scott Brown makes his closing argument:

Lastly, also from the Bay State, below is a novel TV spot from House hopeful Richard Tisei (R-MA) which David Beard calls "the most low-key campaign ad ever":

Ad War archive here.