XKCD Isn't Funny - #1712 - Politifact & #1713 - 50ccs
The implication this comic is giving me is that no one likes Politifact because it comes at trivial facts that don't need to be disputed. See how it climbs in the window for just "I did not sleep well last night"? But the real reason no one likes Politifact is how it points out how all politicians are liars all the time so it's against everyone. Presumably this is the punchline Randy was shooting for, but the context added by the setup changes it.
XKCD Isn't Funny? Politifact says: Mostly True!
This is a stupid pun and I'm a fan of stupid puns. This one passes on humor alone. That said, it is still CouldBeATweet. Were I XKCD's beta-reader or editor, I'd suggest adding a panel where Doctor is being told something by her supervisor or department head or whatever doctors have. Supervisor could be like "...and here's the last of the forms." and Doctor would say "Geez, this is twice as much as I had to fill out for cutting that guy's leg off." or something. That's just one way this could be fleshed out into a Real Comic, though.