It Also Should Be Said Every Incumbent US President In The Last Century That Both Ran For Reelection

It also should be said every incumbent US president in the last century that both ran for reelection and didn't have a severely shit economy has won reelection. Every. Single. One.

That can't be said for every governing party though with losses of Stevenson to Eisenhower or Nixon to Kennedy or Humphrey to Nixon or Gore to Bush Jr or Clinton to Trump.

Right now Biden is the best shot to beat Trump simply because of incumbency advantage. There simply is no severely shit economy like the Great Depression that killed Hoover or Stagflation that killed Carter or 90s recession that killed Bush Senior or COVID recession that killed Trump that could even vaguely justify replacing Biden (though severely bad economies kill non-incumbents even worse).

Plain and simple most US presidential elections are just general approval/disapproval votes of the governing party with exceptions mainly being for incredibly popular challengers challenging a non-incumbent. With most Democrats doing unusually well in polls since Dobbs and most times performing in elections over 5 percentage points better that the polls and 10 points over the previous elections pretending Biden being a couple points down in the polls will kill him in a way it just hasn't for any other Democrat is insane.

It gets even less logical if we factor in Democrats spending way more than Republicans on this election. 90% of the time money wins and when it loses it's almost always to incredibly well run grassroots campaigns which Trump's just isn't. Or the fact the more contested primaries a candidate has the more likely they are to lose and well...

It Also Should Be Said Every Incumbent US President In The Last Century That Both Ran For Reelection

Which one looks more contested?

If you want to look at swing state results:

That's an average of 10 points less for Trump vs Biden as well as over 10 points more for the largest Trump challenger vs largest Biden challenger.

So please how in the world is Biden having an off debate (which very few undecided but will vote voters watch) is justification to kill all of the incumbency, money, and lack of primary challenger advantage Democrats have worked so hard to accrue this election season? Lichtman who's predicted all but one of the previous 10 elections has already came out saying pulling Biden will wreck Democrats chances of beating Trump. Biden isn't perfect but he's the best shot at defeating Trump that we have in November so please can it with the mental decline argument. If that was enough to kill Biden, it would have killed Trump too.