… and pivot to the general election:

The above ad was probably adapted from a month-old RNC memo. Several more Romney spots below. Here's "how to caucus" in Nevada: 

Over the radio in that state, Romeny returns to pro-life defensiveness:

In Colorado, Romney touts endorsements from Chris Christie and Ann Coulter: 

Meanwhile, Santorum's PAC is spending again:  

It turns out that Santorum is quietly leading in Missouri, where the above ad is running: 

[The Red White and Blue Fund] is targeting the Feb. 7 Missouri primary because of a PPP poll that shows Santorum with a 13-point lead over Mitt Romney, the presumptive Republican front-runner, in the state. Newt Gingrich did not qualify for the ballot in the state.

Alex Burns adds

There are no delegates at stake in Missouri, but any win would be helpful for Santorum, and the GOP field as a whole has evidently decided to treat non-binding contests there and in Minnesota, Colorado and Maine with some seriousness.

In other Super PAC news, Gingrich and Adelson will meet later this week.  Previous Ad War Updates here, here, here, here, here, here, here, here, here, hereherehere and here.