Just ask Obama. And Merrick Garland.
So here's where things get complicated. If Trump wins, he probably gets the Senate. If Trump loses, Clinton probably gets the Senate. So, no disconnect, right? Everyone in the GOP wants and needs Trump to win. Everyone is on the same page, right? Go, Trump, right? Not quite. The problem comes if one accepts the premise that Trump has already lost. If we accept the premise that Trump's vote share is somewhere in the range between 46% and 49.5%, disconnects occur. For the purposes of simplification, let's assume the winner gets the Senate (even though it ain't necessarily so).
Trump doesn't care at all about the difference between 46% and 49.5%. Both make him a loser.
So, time for a lesson in microeconomics. Yes, kids, it's back to school time. Utility functions!
Senate Republicans want as many seats as they can get. More seats = better, even with HRC as President because it is easier to block her from doing stuff. She's a lefty, after all. Not a Bernie lefty, but still a lefty. Her brownies are just brownies. So, their utility goes up as the number of seats they win goes up. That goes up as Trump's vote share goes up, regardless of the 50% threshold.
Trump cares only about the 50% threshold. His utility for winning is some "yuuge" positive number because he can brag about winning a big contest, and his utility for losing is some "yuuge" negative number because his incredibly thin skin cannot handle being a pathetic loser.
So, Trump has no incentive to work towards 49.5%. If he thinks he's at 46%, then, he may as well shoot the moon. Apparently with nuclear weapons, even if it risks dragging the party down even more. There's the disconnect. Since Trump's preferences are built exclusively around the 50% threshold, whereas Senate Republicans care about each increment, Trump can and will take risks when he finds himself losing, as he is.
Fun stuff ahead! But not for Ayotte, Toomey, and some others I'll be talking about soon...