170,761,428.5 people are represented by Democratic senators, while only 149,985,163.5 are represented by Republicans. You can check our work here.
An alternative method of measuring how much Senate malapportionment advantages Republicans is to look at the total number of votes cast in the last three election cycles (each cycle, one-third of the Senate stands for election, so the current Senate was assembled from the results of these three elections). According to the voting reform group FairVote, “the 46 Democratic caucus members in the 114th Congress received a total of 67.8 million votes in winning their seats, while the 54 Republican caucus members received 47.1 million votes.”
So the United States Senate is only marginally more democratic than the British House of Lords. The most populous state, California, has 39,144,818 residents and two Democratic senators. Meanwhile, the least populous state, Wyoming, has 586,107 residents and two Republican senators. That means that a voter in Wyoming has nearly 67 times as much input in the makeup of the United States Senate as a voter from California. So much for one person/one vote.