General Discussion

Encumbent advantage is so common you can find hundreds of thousands of links describing it and it even appears on Wiki.

"In general, an incumbent has a political advantage over challengers at elections. Except when the timing of elections is determined by a constitution or by legislation, the incumbent in some countries may have the right to determine the date of an election.

For most political offices, the incumbent often had more name recognition due to their previous work in the office. Incumbents also have easier access to campaign finance, as well as government resources (such as the franking privilege) that can be indirectly used to boost the incumbent's re-election campaign."

Yeah, ALMOST always the encumbent wins. With Carter, Raygun got the Iran terrorist to hold off releasing the American hostages until after the election. This made Carter look awful.

With Bush, his involvement in Iran Contra started to come out with his 2nd election attempt and it made him look awful.

With Pedo Trump.....well he always looked awful, he just looked worse in office with so many dead from COVID. Pedo Trump is regularly voted the worse president in history.

I don't know what criteria you use for awful but to me these are awful things that made these incumbent lose.....note that being older isn't commonly a disqualifier for an encumbent.

There is evidence that many of these "Biden is too old" Dems have been getting funding from uncommon sources. Our elections are awash in unaccountable funds. I doubt Putin is Not joining in on the bribe bonanza.