Now having said all that... The so called LEFT has never been in a majority, either. They too are about a third of THOSE that vote.
LEFT cannot win without the Middle..which is also about a third of those who vote.
RIGHT cannot win without the Middle, either.
True Leftists will vote DEMOCRAT. True Rightists will vote REPUBLICAN.. regardless of who the candidates turn out to be...
ERGO...it follows that the MIDDLE, who will vote either way..for the person, NOT THE PARTY... controls the winning side.