It’s mostly a psychological thing. Having 60 is seen as a benchmark. The Dems have more than a few RINO’s that they can rely on at any time. They’re filibuster-proof, no matter what. (As if the GOP has any Senator with enough guts do it, anyway!)
Sadly, that’s what I thought, too.
Maybe but some issues like raising fuel standards on autos won’t go over well Senators who have auto mfgs. in their states. Don’t expect coal state Dems to put themselves out of jobs either.