The midterm elections 2018 could shift the political landscape dramatically if Congress is split between the Republicans and Democrats.
During the first two years of Donald Trump’s presidency, the Senate and House have both been controlled by the Republicans.
But opinion polls suggest the Democrats could be about to flip the House after consistently low approval ratings for the US president.
Experts say voter turnout could be the highest in a midterm election for the last 50 years.
The Republican Party are largely expected to retain control of the US Senate but lose the majority of the House, according to the latest polls.
At present the Republicans have a 80.9 percent chance of controlling the Senate and the Democrats only have 19.1 percent.
This is because 23 of the 35 seats up for election are under Democrats control and the Republicans have more opportunity to capture them.
In the House, where 435 seats are up for re-election, forecasters say the Republicans only have a 12.1 percent chance of holding control.
Here, the Democrats have an 87.9 percent chance of claiming majority and only need to flip 23 Republican seats to make it happen.