I suspect it's because he made a correct prediction and wanted to brag about it

Joe Crowley, she ran against him and I said, “You know, Joe, you’re gonna lose this thing unless you go out and campaign.” I watched her campaigning a little bit. I happened to turn on television, I saw her campaign. It was almost like by accident. And I said, “You’re going to have to run a little.” “Oh, well, no, she’s a young girl,” he said. She’s a young girl. She’ll be-, I’ve taken on many of them.” And he ended up losing, pretty easily actually

He thinks she would be an easy opponent and thinks he's playing chess by giving her a boost. You know, like Hillary did with Trump.