Honestly, I never paid that much attention to the left/right leaning stuff, probably because I was never into politics at all. Most likely never noticed, and/or didn't care. I just thought it was a given that whoever was in office, was going to get skewered.
I stayed with SNL through Ferrell, Fallon, Kattan etc. My main reason for moving on was the constant turnover. They'd start a new season, and it would go from 8 cast members to 24, and I wouldn't recognize 2 of them. Didn't want to have to start over and get familiar with all the new characters.
It was really after Clinton because they hammered him pretty hard with Darryl and Phil Hartman but at some point it turned from lampooning the administration (which was always a comedic staple, even for Carson) to not-so-subtly attempting to influence people. It became more purposeful. The edge was sharper. And the blade didn't cut both ways. Maybe that really didn't start in earnest until they attached collectively mouth-to-butt to suck off Obama. Fey's take on Sarah Palin went beyond comedy and into cruelty designed to shape public opinion of her - and derail any hope traitor McCain had of becoming president. In retrospect, it's probably a good thing. He was a deep-state Democrat hiding in Republican skin.
I loathed Ferrell. Couldn't stand him. I also hated Adam Sandler on the show. Never funny in any way whatsoever. That was really enough to push me away. About the only thing that was interesting to me during that era was Norm Macdonald and sometimes Dennis Miller. I was never even much of a Chris Farley fan - poor man's John Belushi was all he was.
I think part of that is age, too. I grew out of it. Occasionally somebody sends me a "great" sketch but it's always so stupid and lame I rarely even finish the three or four minutes of whatever it is.
I am grateful for the talents it found. Some of my favorite movies of all time came from the early years crew.
Vacation and Christmas Vacation, Fletch, Ghostbusters, Stripes, Animal House, Trading Places, Beverly Hills Cop, Blues Brothers, Caddyshack, Groundhog Day, 48 Hours, Coming to America. I have to include Elf here, although everything else that idiot rump ranger did is garbage.
Chevy. Dan. Bill. Eddie. John.
Yes, I know some of those younger than me would strenuously object to my rejection of films like Waterboy, Happy Gilmore, Grown Ups, Wayne's World, Click, Austin Powers, Old School, Anchorman, and Tommy Boy from my list, but I wouldn't wake up to poop on any of them. IMO they are all horrible, unfunny, one-note, superficial, superflous trash films. Seen them once, hope to never see them again.
This discussion is actually more entertaining than the film that initiated it.