If there’s an abiding lesson from 2016, it’s that national public opinion in the presidential race is not as important as the votes of individual states. Republican Donald Trump won by taking 304 electoral votes to Democratic nominee Hillary Clinton’s 227, even as Clinton beat him by 2.9 million votes and 2.1 percentage points nationally.
In 2020, Democrats will be looking to recapture states Trump won that went for Democrat Barack Obama in 2008 and 2012. And many of those states will also be prime battlegrounds in the fight for control of the Senate, where Democrats need a net gain of four seats to take a majority (three if they win the White House and the vice president can break 50-50 ties), while Republicans need a net gain of 19 seats to retake the House.