The conservative group Americans for Prosperity is spending nearly $1.7 million on a TV ad criticizing Democratic gubernatorial candidate Gretchen Whitmer, saying she backed policies of former Gov. Jennifer Granholm and voted for tax increases as a legislator.
The 30-second ad will begin airing Thursday and run for three weeks. Americans for Prosperity is backed by the billionaire Koch brothers.
The ad points to Whitmer's 2007 votes to raise taxes to address a budget deficit. It's being released the same week a pro-Whitmer group launched an ad introducing her to voters before August's primary.
A Whitmer spokesman said Wednesday the Koch brothers are attacking Whitmer because they know she is the strongest candidate to beat Republican candidate Bill Schuette in November. He says Whitmer repeatedly took on Granholm in Lansing.