All three races in Florida, Arizona and Ohio will play a major role in whether Republicans can keep or expand their 51 seat to 49 seat Senate majority.
Trump's moves to put tariffs on imports have already factored into races for the House and Senate.
President Trump is trying to help Rep. Lou Barletta, an early supporter Trump supporter, take down Sen. Bob Casey.
Rep. Robert Pittenger lost a primary challenge, while Reps. Todd Rokita, Luke Messer and Evan Jenkins lost Senate primaries.
Senators have asked Carl Icahn and EPA Administrator Scott Pruitt to explain how an Icahn-owned refinery secured a valuable exemption from the nation's biofuels law.
Renacci will face Sherrod Brown, a Democrat defending a seat in a state Trump won in 2016.
In West Virginia, Indiana and Ohio, Republicans will choose nominees who will challenge Democratic Senate incumbents.
Indiana, North Carolina, Ohio and West Virginia will all hold primaries on Tuesday, with big implications for the battle for the Senate and House.
Trump's decision to reconsider joining the TPP opens up another potential line of attack for some Democrats.
The European Union, Australia, Argentina, Brazil, South Korea, Canada and Mexico will get initial exemptions from looming steel and aluminum tariffs from the Trump administration.
Democrats who face re-election in states Trump won in 2016 face pressure to support measures seen as bipartisan.
Trump's proposal to put tariffs on steel and aluminum imports has put strange bedfellows together in Pennsylvania's 18th District.
Even as President Trump threatens to slap protective tariffs, lawmakers are moving forward with legislation to lower trade barriers on hundreds of other products.
President Donald Trump is doing the right thing by proposing tariffs on steel and aluminum, Democratic Rep. Marcy Kaptur says.
President Trump's first State of the Union made a single reference to Russia over an hour and twenty minutes.
The White House decided not to immediately impose sanctions on certain Russian entities, defying a deadline as understood by many Democrats.
Steelworkers thought they would see a new dawn for their industry. But the president’s pledge to do something has actually done more harm than good.
Sen. Al Franken plans an announcement Thursday after new allegations and growing calls for his resignation.
At his Senate confirmation hearing for Fed chairman, Jerome Powell says he favors "tailoring" regulations to help smaller banks.
The senators said the deal was a "blatant attempt to further Allergan's market monopoly" on its $1.5 billion eye drug, Restasis.