The Democratic Presidential candidate has won the popular vote in the last 7 of 8 Presidential elections[0], with the Dems having, on average, about 5 million more votes for those 8 elections. It's empirically fair to say the right represents about 45% of voters (which makes their power even more noteworthy).

[0] year,dem_candidate,dem_votes,gop_candidate,gop_votes

1992,Bill Clinton,44909806,George H. W. Bush,39104550

1996,Bill Clinton,47401185,Bob Dole,39197469

2000,Al Gore,50999897,George W. Bush,50456002

2004,John Kerry,59028444,George W. Bush,62040610

2008,Barack Obama,69498516,John McCain,59948323

2012,Barack Obama,65915795,Mitt Romney,60933504

2016,Hillary Clinton,65853514,Donald Trump,62984828

2020,Joe Biden,81268867,Donald Trump,74216747