Ok, so the most logical explanation for this is a career politician at the apex of his career did this despite the fact that the vast majority of people and his colleagues hearing about it would think he was a nut job. And he did this, risking appearing mentally incompetent to his financial backers, the party members who made him majority leader of the Senate, and his constituents to secure the votes of a fringe ufo motivated voting block.
Edit - actually your thesis is he did this without necessarily even wanting those fringe votes. Sounds like he is not making very good decisions.