Sure there exists a "huge anti trump demographic," but unfortunately that demographic exists in Blue States or urban areas outnumbered by rural districts in red states. Remember, more Americans voted for Hillary largely cause they disliked Trump, but he still won, it comes down to three or four States, and that aren't part of the "huge anti Trump demographic"
Republicans have to defend 22 States, but the overwhelming number of them are in red states, only three or four up for grabs, meaning the GOP is the favorite to retain the Senate
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