Schmidt, of Traverse City, will face fellow Republican Rep. Greg MacMaster in the Aug. 5 primary for the 37th District seat.
MacMaster's mother, Michele, told the Traverse City Record-Eagle that Schmidt is "the better candidate," citing his background and community activities. She declined to discuss her relationship with her son.
Greg MacMaster, of Kewadin, said he hasn't spoken to his mom in 21 years and said she left him to live with his alcoholic father as a boy. Once his dad died, he later lived with his mother and stepfather.
It's "unfortunate some people choose to take politics to a personal level. For voters, politics should be about my positions, the votes I have taken, my conservative values," MacMaster said.
The 37th District includes eight counties stretching from Grand Traverse northeast into the eastern Upper Peninsula. Sen. Howard Walker, R-Traverse City, decided against seeking a second term.
In a statement, Schmidt thanked Michele MacMaster for her support.
"Politics can bring out many differences among friends and families. ... I believe we should laud participation, not criticize and attack family members who disagree with our political choices," he said.