Republican U.S. Rep. Fred Upton says he is not planning to endorse Donald Trump for president, deepening the divide in Michigan’s GOP congressional delegation about supporting the party’s presumptive nominee.

House Energy and Commerce Committee Chairman Upton, who has the most seniority among the state’s nine GOP delegation members, suggested the campaign of the New York businessman has gone “off the track.”

“I’m going to stay in my lane,” Upton, R-St. Joseph, told Holland radio station WHTC-AM on Tuesday while discussing the likely general election matchup between Trump and presumptive Democratic nominee Hillary Clinton.

“There’s a lot of things that folks are not happy about with either of these two candidates,” he said. “We’re running our own race, and don’t look for me to endorse anyone in this race probably the rest of the year.”