I think there are enough voters, but not with the current FPTP and electoral college system. In my native country people vote for their candidates in a first round, then the top two candidates (by popular vote) go into the second round and people vote again between those. That way people are not afraid to cast their vote to their actual first choice like in the US (“if I vote for this 3rd party, I’m just helping the party I don’t like to beat the other party I don’t like that much either but it’s not as bad as the first one”).
I think there are enough voters, but not with the current FPTP and electoral college system. In my native country people vote for their candidates in a first round, then the top two candidates (by popular vote) go into the second round and people vote again between those. That way people are not afraid to cast their vote to their actual first choice like in the US (“if I vote for this 3rd party, I’m just helping the party I don’t like to beat the other party I don’t like that much either but it’s not as bad as the first one”).
If we had a less bipolar system things would look very different.