...The Liberals and NDP usually collect over 50% of the popular votes. The Conservatives usually under 40%....
Someone who votes NDP or Green is very likely to be on the Left, politically. Someone who votes for the Liberals or Conservatives does not necessarily support that Party; they might be voting against the other.
Both the Left and the Right are minority positions among all adults. The biggest demographic is those who don't care about politics, so they don't bother to vote.
In the 2018
Ontario General Election, the Conservatives won a majority government with 40.5% of the popular vote. 56.67% of eligible voters cared enough to cast a ballot, so 22.95% of eligible voters, (40.5% of 56.67%), voted Tory, or slightly more than 50% of the non-votes not received by the Don't Give a Shit party,representing 43.33% of the eligible voters. A fair percentage of the Conservatives' 22.95% support was citizens voting against the lesbian who looks like Orville Reddenbacher, whose name escapes me at the moment.
Some people vote for the NDP because they want the Party to have some presence in the Parliamentary House, if only to provide a social conscience to the legislative procedure, but like the majority of citizens, they shudder at the concept of what happens when those naive idealists actually wield power.