This, then, is the nub of Warren’s problem. It is not that she is liberal. It is that the issues on which she has taken the most prominent liberal stances are issues that are likely to give suburban whites pause. In particular, her pledge to abolish private insurance is likely to cause resistance among suburbanites, many of whom have top-notch health care plans.

You may be thinking, “But Republicans will accuse any Democrat of being an extremist on health care.” This is probably true. But most Democrats will be able to run commercials and point to speeches denying the claim. For voters who want to vote Democratic, that will probably be enough. Warren, however, has to make a different argument: “Yes, I want to do away with private insurance, but your anxiety over Medicare for All is misplaced.” That’s a much tougher sell, as it forces voters to abandon their preconceived notions, rather than supplement them.

Or, as one of my readers put it: There’s a big difference between having a Republican attack ad run against you, and running on a Republican attack ad.