Florida Sen. Bill Nelson is one of 10 Democrats up for re-election next year in states that Republican Donald Trump won in 2016.
Republicans, on the other hand, have only one Senate incumbent — Dean Heller of Nevada — facing re-election next year in a state that Democrat Hillary Clinton won.
The contours of the 2018 Senate map fuel Republican optimism about keeping their Senate majority despite Trump’s low approval ratings and polls showing a Democratic advantage in generic congressional ballot tests.
But a new analysis by University of Minnesota politics blogger and master data cruncher Eric Ostermeier gives Democrats reason for optimism in Florida and the other Trump states they’re defending in 2018 Senate races.
Voters in those 10 Trump states — particularly Florida — have a tendency to vote against the president’s party in Senate elections over the last 50 years.
If that trend holds, it’s good news for Nelson, who could face a strong challenge from Republican Gov. Rick Scott.
In 17 Senate elections since 1966, Florida voters have chosen the nominee of the president’s party only 5 times — 29.4 percent.
Nelson did it twice. He initially won his seat in 2000 while Democrat Bill Clinton was president and he won a third term in 2012 while Barack Obama was president. Republican Mel Martinez won a 2004 Senate race during Republican George W. Bush‘s presidency. Republican Connie Mack (1988) and Democrat Bob Graham (1998) also won Senate races while their party had the presidency.
In 12 other Senate races — including both of Republican Marco Rubio‘s victories — Florida voters chose the nominee from the party out of the White House.
Ohio voters have been the toughest on the president’s party, voting for the Senate nominee of the party that controls the White House only 4 times in 17 races.
Missouri voters, on the other hand, have chosen a Senator from the president’s party 11 times out of 17, or 61.1 percent.