Presidential candidates take note: If you ever want an effectively simple campaign slogan, you could do worse than this: “SHE FUN!”That’s the slogan that got President Judy Gagwell — aka RuPaul — elected, and if it puts a smile on your face, it’s a good sign that lots of other, er, gags from Gagwell and others in “Stop! That! Train!,” a delightfully absurd disaster-flick spoof with a wildly impressive joke-per-minute ratio, will be up your alley, too.Especially when RuPaul is on the screen, in presidential pantsuits recalling Hillary Rodham Clinton or Kamala Harris. A memorable visual moment in director Adam Shankman’s film is when RuPaul’s prez is being briefed, during a White House corridor walk-and-talk a la “West Wing” and “Veep,” while her chief aide (a hilariously sycophantic Matt Rogers) is also gravely piling things into her arms. He starts with briefing papers but moves on to ridiculous items like a bowling pin, a board game and a stuffed animal.

Even funnier is when the president, seeing that her aide has bad news to impart, asks: “Tell it to me straight.” He informs her of the catastrophic storm — the “Stormaganza!” — in the path of a runaway train full of passengers. Then she says: “Tell it to me gay.” And he just screams.