No. The Klan will vote Republican, ELF will stay home or vote for a third candidate. And, as things stand presently, if we draw the line to extremism at some common measure of anti-democratism and/or support for organised violence against political opponents, the right-extremists are a much larger group than left-extremists. For that reason, any equation of left/right-extremists only serves the Right's pursuit to move the center further right, defining ever milder leftists extremists (and ever viler right-wingers just hard- or centre-right).

_{*Lunatic*, n.
One whose delusions are out of fashion.}

I was surprised to learn in an earlier comment thread that France uses FPTP and that the multi-party landscape is supported mostly by agreements at the party level where the PS negotiates not to contest a few seats where some other left party has a chance or a prominent candidate.

"It's the statue, man, The Statue."