The Senate election is increasingly nationalized, and even well-known incumbents face a powerful tide as money pours into Democratic campaigns.
Iowa, which Trump won handily in 2016, a Des Moines Register poll in June found GOP Sen. Joni Ernst — whose race was not considered competitive just months ago — narrowly trailing her Democratic challenger, real estate developer Theresa Greenfield. The survey also found Biden essentially tied with Trump.
A top GOP strategist, speaking on condition of anonymity to assess his party's candidates, said he remained confident about Montana, Georgia and Iowa. He worried most about Arizona, Colorado and North Carolina, he said.
If those three states fell, Senate control could all come down to Maine, he said, and Collins’ ability to withstand a possible anti-Trump wave.