What changes if Democrats win a majority in Congress?

Americans head to the polls on Tuesday for the US midterm elections, which could flip the majority in one or both houses of Congress from the Republicans to the Democrats. What would a Democratic majority mean for the country's political landscape, and how might Democrats move to keep President Donald Trump in check?

Americans head to the polls on Tuesday for the US midterm elections, which could flip the majority in one or both houses of Congress from the Republicans to the Democrats. What would a Democratic majority mean for the country's political landscape, and how might Democrats move to keep President Donald Trump in check?