McConnell wins. The Republicans have 51 votes. The first thing McConnell does is change the filibuster requirements back, necessitating the Republicans get 60 votes (votes they can't get) to move bills forward.
McConnell promised this, even though Dingy Harry made this rule change to give cover to McConnell so he could have plausible deniability and “look” conservative. McConnell, as leader, gives this power back to Dingy Reid to again give himself plausible deniability (because, “we can't pass anything without the Democrats onboard”).
McConnell has been up 0bama’s butt so long that if his head was removed, he could no longer adapt from a pure methane atmosphere back to oxygen, and he would die of suffocation.
Your point makes more sense with Republicans who aren't so “smart” as to always only do something to “get along” with Democrats. McConnell is, by principle, either a liberal or a limp-wristed moderate who can't ever be counted on for standing upon conservative principle.
McConnell is neither liberal or limp-wristed. He's a craven Quisling who sold his soul to the statists and thrown his hard-working-class constituents under the bus. Why? So that he can continue to be feted by the powers-that-be "Inside the Beltway" and live off the fat of the land.