The daily 538 cratering of Sanders continues unabated, on the verge of going sub 20% for 1991

[TwilightZone]

8. They don't care.

All they care about is winning. If the convention is contested and they lose, the fact that the convention was contested is irrelevant.

"I believe that for most liberals, the process by which our party chooses a candidate still matters."

That's why there's a process. All of the candidates agreed to the process by running as Democrats, and some, including Sanders, were involved in setting the parameters.

"it is quite likely that there will be hard feelings from some of their supporters. "

There will be hard feelings regardless. In 2016, Clinton beat Sanders 2:1 among Democrats and won the nomination handily prior to the convention, and some Sanders supporters still went ballistic, then stayed home or voted for Stein.

We shouldn't make decisions based on the actions or attitudes of the worst of the worst. Appeasing people who are going to be unhappy regardless gets us nowhere. We tried that in 2016 by giving Sanders influence at the convention and members on the board and a chunk of his supporters stayed home anyway. It's a no-win where some of them are concerned.