An Amendment to the U.S. Constitution should be passed whereby U.S. Senators and House of Representatives must win with a majority of the General Election votes. If there’s no candidate with more than 50% of the vote, there would be a runoff election the first Tuesday in December with the two candidates with the most votes the only names on the ballot. The winner of the runoff wins the seat.
This way a candidate gaining less than half the voters’ choice wouldn’t be elected.