It's a hard theory to test since we actually have never had a Dem nominee (since Dukakis) who is as far behind at this point in the election as Trump is behind Harris now. But if that were the case I doubt they'd be propping him up, they'd be burying him as a failure.

When a Democrat is winning they need to be knee capped to help the Republican, when a Democrat is losing it only makes sense to kneecap the Democrat further so you get in cozy with the Republican

John Kerry really was slightly behind (not as far behind as Trump but behind) in September polling and the media did not respond by propping him up but by running dozens of stories promoting a slanderous lie about Kerry's heroic military career. It makes you think!

Trump is the media’s ratings golden goose and their chosen candidate.

I mean, we saw how they reacted with Biden — like sharks detecting blood. Of course in the process they accidentally did the Democrats a huge favor.

we thought Trump was further behind Biden at this point in 2020, iirc (even though the polls were wrong), but they didn’t bury him then

I was only a teenager at the time, but the media absolutely joined in the pile-on against Dukakis back then. Willie Horton, the polluted Boston harbor, the tank photo op… the media helped push all of those stories and then tut-tutted about his debate performance.