What’s unclear to Trump-backing Republicans: the degree to which the president’s base support in the industrial Midwest is waning or holding fast; whether the young minority voters who failed to show up for Hillary Clinton after supporting Barack Obama will return to the next Democratic nominee; and whether the power of Trump’s political celebrity is wearing off.

They also don’t know if Democrats are at risk of losing unexpected battlegrounds that were closer-than-expected in 2016, or whether Hispanic voters will turn in greater numbers against the president after four years of hearing about deportation forces and a border wall.