In this case it's used as a generalized term of reference for any unspecified person or thing. It's usually used to imply some intense, impressive, or remarkable trait. For instance: 1) You see this computer chip? This little sucker is worth more money than your whole car! 2) The guy we hired for protection is a tough sucker, so I'm not too worried about anyone trying to hassle us. You can use it this way to emphasize the fact that you're impressed by something. As Biden found himself impressed by Ford's speed in this video.