Donald Trump on Sunday ranted at a rally about batteries and shark attacks, leading the internet to question the ex-president’s mental capacity. Trump on Sunday spoke in Las Vegas, at one point veering off into a discussion about shark attacks while apparently discussing President Joe Biden’s environmental priorities related to electric vehicles. “It must be because of M.I.T., my relationship with M.I.T., very smart, I say, what would happen if the boat sank from its weight, and you have this tremendously powerful battery, and the battery is now underwater and there’s a shark that’s approximat…