The question of who controls the Senate may get a little trickier after the November election as the odds of a 50-50 split in the chamber look increasingly likely.
To flip the Senate, Democrats need a net gain of three or four seats, depending on whether President Trump and Vice President Mike Pence win a second term, or presumptive Democratic nominee and his soon-to-be-announced running mate occupy the West Wing. The vice president breaks ties on Senate votes and may be needed a fair amount.
Attention will increasingly be focused on competitive races in Colorado, Georgia, Iowa, Maine, Montana, and North Carolina, among others.
But each of those states contains unique electoral dynamics, meaning a general Democratic wave won’t necessarily carry each candidate across the finish line. Similarly, Trump and the Republican Party can’t anticipate they’ll maintain control of the Senate should the president reverse his current unpopularity and eke out a victory.
Leaving out the toss-up races, both Republicans and Democrats enter the November election with 47 safe seats apiece, assuming the GOP holds onto its seat in the Georgia special election and Democrats remove Arizona Sen. Martha McSally from office. Also, Alabama Democratic Sen. Doug Jones is highly likely to lose the seat he won in a fluky December 2017 special election.
Should Montana Gov. Steve Bullock fail in his attempt to oust Republican incumbent Steve Daines, the GOP would need to grab just two more seats, the easiest likely being Iowa where Joni Ernst is up for reelection. Trump currently holds a narrow lead in the state, meaning Democrats would need heavy split-ticket voting to pull challenger Theresa Greenfield across the finish line.
But Democrats can count on some of their own coattails, particularly in Colorado. There, Democrats hold a steady lead not only in presidential polls but in the Senate race where GOP incumbent Cory Gardner consistently falls behind former Democratic presidential candidate and state Gov. John Hickenlooper.
Those two outcomes would grant the GOP 49 seats to the Democrats’ 48, meaning control of the chamber would come down to races in North Carolina, Maine, and Georgia’s other seat currently held by David Perdue. Should Perdue fight off Democratic challenger John Ossoff, the Republicans would enjoy 50 seats.
Democrats could then sweep both North Carolina and Maine, making the makeup of the Senate at 50-50, with neither party in control, the first time since the 2000 Senate election cycle. During that time, party leaders Republican Trent Lott and Democrat Tom Daschle created a power-sharing agreement that effectively evenly split committees with staffers from both parties.
Passing legislation, however, would likely remain a partisan affair as the vice president is constitutionally tasked with breaking any ties in the Senate. Nor did equilibrium last long in 2001, after the new senators were sworn in at the start of the 107th Congress. Vermont Sen. Jim Jeffords, long considered a liberal Republican, announced his resignation from the GOP following the passing of the Bush tax cuts, handing control of the Senate to the Democrats until early January 2003.
