Twitter makes it easy to realize that the purpose of "fact-checkers" is most commonly rushing to defend resident Joe Biden from misinterpretation... and mockery. On Sept. 20, Twitter warned, "A video of resident Biden discussing hurricane preparedness has been edited out of context, according to fact-checkers." Tweets aired this clip of Biden from Aug. 10: "Let me be clear: If you're in a state where hurricanes often strike -- like Florida or the Gulf Coast or into Texas -- a vital part of preparing for hurricane season is to get vaccinated now." It's easy to see his point: You may...