Wisconsin Republican Governor Scott Walker, who has been running TV ads for months in an effort to insulate himself from a growing recall campaign, went on the air Thursday with ads attacking two potential Democratic opponents.

The ads reflect the challenge confronting Walker, who will face a recall election on June 5, as he waits for the gubernatorial primary in early May. With the general election just a few weeks after that, Walker’s strategists have apparently concluded it’s better to hedge their bets and negatively define the two likeliest Democratic nominees now.

The first spot tears into Milwaukee Mayor Tom Barrett, who was defeated by Walker in 2010 and wants another crack at him:

Likewise, the second Walker ad accuses labor-backed former Dane County Executive Kathleen Falk of reckless tax-and-spend policies:

It will be interesting to see whether outside groups and Super PACs backing Walker’s campaign — like the Koch Brothers-funded Americans For Prosperity — take a similar approach with their TV ads.