While most media attention on United States politics is focused on the potential nominations for President for the November 2016 elections, 34 United States Senate seats are also falling vacant.
The Republicans currently hold a small majority of 54 seats in the 100-seat Senate. The Democrats hold 45 seats, and there is one independent.
Two independent senators had been elected, but one of them – Senator Bernie Sanders of Vermont – was close to the Democrats and has now officially joined the party; in fact he is running for the party’s nomination for president.
The other independent – Senator Angus King of Maine – also broadly supports the Democratic side.
One-third of the Senate seats come up for election every two years. 2016 happens to be the group – called ‘class III’ – in which 34 seats fall vacant; the other two cycles each see 33 seats face election.
The group facing re-election in November were elected during a ‘Republican tide’ at the 2010 mid-term elections. Just 10 of these seats are currently held by Democrats, and 24 by Republicans.
Many seats are held safely in states with strong partisan majorities. Four Republicans and one Democrat won their sets in 2010 with more than 70% of the vote, and one more Republican – Senator John Thune of South Dakota – was so safe that no-one nominated against him.
Overall, around 15 seats are safely held by Republican senators and 8 safely held by Democrats. The remaining 11 seats are considered reasonably contestable.
Of these 11 vulnerable states, 9 are being defended by Republicans, and just 2 are defended by Democrats.
In November 2016 the Republicans need to defend 9 vulnerable Senate seats they won in 2010 (red); the Democrats are defending just two vulnerable seats (blue); pale colours indicate safe seats facing re-election
Republicans are defending the vulnerable seats of Senators Dan Coats (Indiana), Richard Burr (North Carolina), Kelly Ayotte (New Hampshire), Rob Portman (Ohio), Roy Blunt (Missouri), Ron Johnson (Wisconsin), Pat Toomey (Pennsylvania), and Mark Kirk (Illinois). In addition presidential contender Senator Marco Rubio is not seeking re-election to his seat of Florida.
Six of these Republican defenses are in states where President Obama won the vote in his re-election in November 2012; Florida, New Hampshire, Ohio, Wisconsin, Pennsylvania and Illinois.
Democrats must defend the Colorado seat of Senator Michael Bennett, and Democratic Senate Leader Harry Reid is retiring from the Nevada seat he has held since 1987.
Three Republicans (Senators for Indiana, Louisiana, and Florida) and three Democrats (Senators for Maryland, Nevada and California) are not seeking re-election.
These ‘open’ seats are usually considered more contestable, leaving the seats in Indiana and Florida even harder for the Republicans to defend.
Some analysts would add the Republican seat in Alaska and the Democratic seat in Washington into the contestable category. Of course, the voters could create upsets in any state.
Most predictions, therefore are for the Democrats to be quite likely to pick up at least the 4 seats they need to balance the Senate. They have good prospects for picking up the 5 or more seats they need for a majority.
But in November 2018 the Republicans will have a similar historical advantage, anticipating mid-term gains in a number of contestable seats won by the Democrats in 2012.
Any small Democratic majority which emerges after this years election may, therefore, only last for the first two years of the next presidential term of office.