I think you're old enough to remember the jokes about how both parties agree on basically everything, right? On Iraq, on free trade, on being hard on crime, om foreign policy in general, even on gay marriage.
It was basically the particulars, the tiny details, that they differed on.
...No it wasn't.
Democrats never really supported the war in Iraq; they briefly pretended to because it was popular, but that didn't last long.
Free Trade is the only one you
're
probably correct on, but even then, 'they get to layer tariffs against us, we put none against them' is not actually free trade, even if both parties were willing to put up with it for a long time.
The Democrats were the 'soft on crime' party back when that policy first became popular, and only temporarily made gestures about reversing their public stance when it became clear just how disastrous it had been. Now they're back to their old tricks again, and if you look at leftist academics and talking heads, they've been pushing for it again at least since the 90's.
Democrat foreign policy is best summed up between Obama's apology tour and Biden's obscene corruption. For any other faults you may care to name, every Republican in living memory has presented a strong America to the rest of the world, and has been willing to kick ass and blow shit up to make sure people know we're not to be trifled with.
Democrats have supported basically every sexual deviancy since the start of the sexual revolution in the 60's; how much they had to pretend to be good upstanding Christians to keep their share of the upper-middle class and lower-upper class WASP vote has varied by decade, but the left has been allied with the 'rainbow' crowd for my entire lifetime and then some. Up until Trump, every major Republican politician and candidate was against such things.
The two parties have held drastically different public stances on practically every major issue since the end of WWII, certainly since JFK died.