Not so. Washington wasn’t a gung-ho revolutionary republican. Lincoln was no rabid abolotionist. Jeff Davis believed secession was legal, but not that the South should secede. At the time all of them were regarded as moderates on the great issues of their day.
What does “politically moral relativist” mean? A cynic might explain it thusly. Certain political opinions (like gun control, pro-choice, national health service) have become thought of as “leftist”. Others, (such as anti-abortion, pro death penalty, free market) have become associated with the right-wing.
This has become so entrenched now that someone who holds an opinion on say, creationism, is by definition also expected to be in favor of, say, tighter immigration controls. Someone who thinks for themselves and refuses to buy into this, by say, believing in increased defense spending and also that we should reduce Carbon emissions, is accused of being “unprincipled”!
Political moral relativism - its just another excuse not to think.