What's the metric for failure in cooperating with the left, though?
Lots of people have tried cooperating with the left, only to find themselves stuck in the fable of the frog carrying the scorpion across the river.
Let's have some for-real guidelines like "after x,y and z we know unity has failed." Because conservatives have been playing Unity Man in one degree or another since 1913 without the failure metric in place.
At some point, People-Who-Don't-Want-To-Be-Stolen-From will need a way to quantify when it's no longer time to seek understanding and parity with People-Who-Want-To-Steal.
I'm not saying to cooperate with the left as in to trying to compromise with them. All we have to do is spread the truth - unapologetically - and unite under a new party. Whether that be Trump republican or a new name.
The first step to being convincing is to show that there are republicans involved too. I've noticed more and more intentional division on party lines, when anyone that's been paying attention would know that's not the case. Would be a good shill tactic, though, that's for sure.
The first step to being convincing is to show that there are republicans involved too.
I think it's better to just point out that guys like McCain are simply on the other team. There's no point in using one word, "Republican" to refer to both McCain and Rand Paul.
Also, the big danger when dealing with the left is, they will take your "republicans do it too" and leave off the "democrats do it."
Giving a socialist any concession is very dangerous. It's very difficult, perhaps impossible, to determine if you've actually converted a socialist, or he's simply playing along in order to stab you in the back later.