You didn’t need to be Sherlock Holmes to work this one out, but Bruce Rastetter helpfully confirmed today that he will support State Senator Rick Bertrand’s GOP primary challenge to Representative Steve King in Iowa’s fourth Congressional district.

Assuming Rastetter puts his money where his mouth is–and years of disclosed and undisclosed political contributions suggest that he will–he may become a major donor to Nick Ryan’s effort to take out seven-term incumbent King.

Early in last year’s legislative session, state lawmakers voted to raise Iowa’s gasoline tax for the first time in more than two decades. Unlike many controversial policy questions, this issue did not split the public or elected officials along party lines. The Des Moines Register’s February 2015 statewide poll showed Iowans generally and subgroups of Democrats, Republicans, and independents were all divided on whether to raise the tax by 10 cents a gallon to pay for road and bridge repairs. In the Iowa House and Senate, lawmakers from both parties voted for and against the tax increase. Senate Majority Leader Mike Gronstal had reportedly refused to bring the bill to the floor without a guarantee that at least half of the 24 GOP senators would vote for it.

The immediate backlash against the gas tax hike came mostly from Republican circles. Former Iowa GOP Chair A.J. Spiker and former state party co-chair David Fischer were among the vocal critics. Conservative WHO Radio host Simon Conway urged Republicans to “send a message” by changing their party registration.

Governor Terry Branstad signed the gas tax hike into law within 24 hours of its passage. The following day, conservative activist Eric Durbin announced on Conway’s show that he would challenge nine-term incumbent State Representative Clel Baudler in the 2016 GOP primary to represent Iowa House district 20.

Yet a year later, there is little sign of political fallout for the 28 state senators and 53 state representatives who voted to make Iowans pay a little more at the pump.