Not really.
US population: 314M. Eligible voters: 207M.
Number who voted: 125M. That number may go up a little as states certify the vote totals.
125M is 40% of 314M, but 61% of 207M.
Number of registered voters is considerably lower than 207M, but I couldn't find a number.
Stats were acquired from several sources, and may not all apply to the same year, but are likely to not be too far off.
Polls over the last decade have routinely shown that those who are eligible but don't bother to register or vote usually favor the Democrat by more than 2:1 over the Republican.
Well that is encouraging.
LLS