The problem is that the nationalization of US politics and the nationalized Southern Strategy predates Trump. This Urban v Rural. diverse vs white supremacist, Survey Corps vs Titans war was coming regardless of if we wanted it.Look, I don't think our chances of taking the senate back are great in 2020, or 2022, or 2024... but I also think there's a good chance American politics is going to look very different in 2029. Post Trump, who knows what condition the GOP are going to be in? Which states will be swing states? Etc.
And the public just doesn't punish people for playing inside baseball. So add the states, it's the right thing to do and the right political thing to do to maintain power and start playing the deck against the GOP.