The problem is that Ryan is a True Believer in mass immigration, offshoring, massive trade deficits and so forth, in other words open borders.
Mitch McConnell, on the other hand, is just bought by the Donor Class and does what they tell him to do. If the Donor Class for some reason were to tell him to renegotiate the trade agreements, he would then be for that.
But Ryan is a globalist ideologue, and more and more Republicans are beginning to realize that.
Ryan appears to be the closest thing to Cassius (plotter and assassin) in modern US history. It’s not ideology, it’s pure scheming ambition.