With 129 days left until the US midterm elections that will renew the House of Representatives and a third of the Senate.
Republicans currently control both chambers by narrow margins. In the House of Representatives they hold 218 seats against 212 Democrats. In the Senate the advantage stands at 53 to 45.
Democrats lead the generic ballot by five to six points. Donald Trump's approval rating hovers between 37 and 40 percent.
The war with Iran that began on February 28 and the ceasefire signed on June 17 shape the landscape. A divided government appears the most probable outcome according to forecasters.