It ain't gonna be him. He's too senior.
And frankly, touting Brown as some sort of sign that MA is going conservative is, well, horseshit. As he's shown so far, he's anything but. If he WAS acting like a conservative in the Senate, he'd be out on his ass next year, and you know it.
Finally, at the state level, nothing changed, nothing will EVER change. Even you can't deny that, fl.