[1] https://en.wikipedia.org/wiki/2008_United_States_presidentia... [2] https://en.wikipedia.org/wiki/2012_United_States_presidentia... [3] https://en.wikipedia.org/wiki/2016_United_States_presidentia... [4] https://en.wikipedia.org/wiki/2020_United_States_presidentia...
Even if you read “voting for a D or R candidate in a Presidential general election” as “being a D or R”, and “eligible voters” as “the American population”, both which are clearly and wildly wrong, your evidence still doesn’t support your claim, because it has 98.2% of 66.2% = 65% of eligible voters, which is not “well above 90%”.
PS Americans also overwhelmingly vote either Democrat or Republican in non-presidential elections, even down to the city council level.
Americans overwhelmingly abstain rather than voting for any of the offered candidates, Democrat, Republican, or independent or minor party, in non-Presidential elections. 2018 had the highest midterm turnout since the before the Reagan era, and it reached the whole way up to 49%.