system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5, if the majority of the American people picked a democrat for president, why did they keep a Republican congress?
gpt
Simply put, people hate congress, but like *their* congressman or woman.  Most congressmen, especially from the house of representatives get elected more on personal appeal than politics.  This goes back to the forming of the house of reps, which was intended to be the group that most represented the people, while the senate was supposed to be full of experienced officials who made judgements for the good of the nation rather than their constituencies.  In addition, many of them have been there a long time, and have a personal relationship with people in their area.

Another thing, As you probably know democrats do well in large cities, while republicans do well in rural areas.  And as it so happens, the vast majority of the country is rural.  Even the states that go democratic tend to have large swathes of relatively rural areas that go republican.  So a state that votes for Obama might have say, 8 congressional districts, only two or three of which are strongly democratic, but those that are contain cities and are VERY democratic.  The other 5 or 6 districts may be majority republican, and so they elect republican representatives, but they do not have enough republicans to counteract the major democratic strongholds, so the state as a whole goes democratic.