Mitt Romney threw his support behind Arizona state Speaker Andy Tobin on Monday, marking the latest candidate Romney has  endorsed in the midterm elections .  

Other Republicans backed by Romney this cycle include Idaho Rep. Mike Simpson, who is facing a competitive GOP primary next month, state Del. Barbara Comstock in Virginia’s open 10th District, and state Sen. Joni Ernst for Iowa’s open Senate seat, among others.  

“I am proud to support Andy Tobin for Congress,” Romney said in a statement. “Andy is a proven conservative whose leadership in Arizona has been crucial to cutting state government spending, lowering taxes and fighting to stop ObamaCare.” Tobin is one of a handful of Republicans looking to oust Democratic Rep. Ann Kirkpatrick in Arizona’s 1st District. Tobin will face state Rep. Adam Kwasman and businessman Gary Kiehne in the Aug. 26 primary, one of the latest primaries in the country.  

The district shares a large percentage of the state’s northern border with Utah, where Mitt Romney is widely popular. He carried this district in 2012 by 2 points, as Kirkpatrick won re-election with 49 percent of the vote.  

Arizona’s 1st District is rated a Tilt Democratic contest by Rothenberg Political Report/Roll Call.