There’s a pretty good kibitzerpalooza taking place around the pending Scott Brown/Elizabeth Warren bakeoff for the U.S. Senate.

In this corner: The League of Conservation Voters, which has launched a $1.8 million ad campaign targeting Brown over his alleged connections to Big Oil. (Hardworking staff coverage of the group’s first ad here.)

Now there’s a second ad, which depicts a guy in a barn jacket leaving oily footprints and handprints wherever he goes.

Meanwhile, Karl Rove’s Crossroads GPS is dropping 600,000 large on Warren’s head with this spot:

Look for even more money to enter this race soon.