I would hope that people would pay attention to facts — to polling, specifically. We have the technology to conduct very effective polling when we want to, and we should determine where the “center” lies by identifying which policies meet with majoritarian support among the American people.
For example, a Single Payer, Medicare for All type healthcare system is something that enjoys strong majoritarian support. Democrats and Independents support it by well over 60%, and even a slim majority of Republicans who earn $35K or less support this.
This majority support for single payer was even reported in The Blaze — certainly not a liberal source.
So — we can say that anyone claiming to be “centrist” should support Medicare For All.
See? Not that hard.