Sharks gotta swim, bats gotta fly, and surrogates gotta go on the attack to quash criticism of The Queen, or something. Sen. Claire McCaskill (D-MO) showed up on Morning Joe with a 4×8-sized chip on her shoulder for the criticism Hillary Clinton was getting for her flip-flop on TPP. Lots of people change positions, McCaskill says, and tries to change the subject to Jeb Bush and Marco Rubio on immigration — which drew some sharp retorts from Joe Scarborough and Mika Brzezinski:

Sen. Claire McCaskill (D-Mo.) on Thursday took aim at MSNBC’s “Morning Joe,” asserting the show is treating Hillary Clinton unfairly.

“Everybody evolves on positions,” McCaskill said of Clinton during a testy interview with hosts Joe Scarborough and Mika Brzezinski.

“I’ve been listening to you guys this morning and I think some of it has been unfair and not balanced,” McCaskill said of the show’s coverage of Clinton’s position on the Trans-Pacific Partnership (TPP).

“I really don’t think that this is an indication that she is somehow unprincipled or weak,” she added. “I think that’s totally wrong.”

Really? In nearly the same breath, she accuses both Rubio and Bush of pandering to Donald Trump’s supporters with their supposed changes in immigration policy. That’s some fancy tap-dancing there in service to what is an excruciatingly obvious pander by Hillary to the unions on free trade. Let’s not forget that Hillary hasn’t just taken a position on TPP once — she’s bragged in public about her role in it more than 40 times, and even included it in her memoir Hard Choices. And she’s obviously doing it to pander to Bernie Sanders’ voters.

Scarborough announced this week that Morning Joe would not allow surrogates for candidates to appear until the candidate him/herself made a personal appearance first. McCaskill probably qualified for the ban list after this threadbare surrogacy for Hillary.