Stabenow is one of 10 Senate Democrats up for re-election next year in a state that GOP President Donald Trump won in 2016. But it is unclear whether national Republican groups will spend heavily in the general election now that Upton has opted out. “Given how many other Senate races are out there, I don’t know if Michigan is ever going to fully activate as a top-tier race,” said Kyle Kondik, managing editor of Sabato’s Crystal Ball at UVA’s Center for Politics.