Thanks to demographics, the Republicans have a virtual stranglehold on the House of Representatives.
While the first reaction might be to blame partisan redistricting (a.k.a. gerrymandering) for the the political gridlock between the presidential results and House of Representatives. Gerrymandering does play a role, but the spatial concentrations and distributions of voting constituencies explain why the Democrats have recently won the popular vote in 5 out of the last 6 presidential elections, but can’t control the House of Representatives. Metro areas are highly left-leaning, currently creating a national majority for Democrats, but that high concentration is a drawback when trying to win a majority of the seats in the House. This is a good article as a primer for electoral geography.