Strong & logical argument
@Zugzug. I think you're right in stating that there are Democrats who hold a strong and firm belief in centrism and act on their principles & I don't think all of them are opportunists.
What I find interesting is that the balance between idealism and pragmatism is more in conflict for most moderates than progressives. Citizen's United comes to mind. The Democratic leadership has once stated that they want to overturn this, but at the same time they say that, as long as it exists, they want to accept unlimited donations from corporations during elections to level the playing field with the Republicans, who have no moral objection against CU. Not only is this a hypocrite thing to do, it also has political consequences, namely that accepting corporate donations influence voting behaviour of some moderate Dems and make them in certain cases not any different from the pro-business Republicans. The Progressives (except Elisabeth Warren maybe) at least recognise that accepting corporate donations and serving people don't always mix together.
Some moderate Democrats are no different from Republicans in some respects. Just as republicans, most moderate Democrats are strongly dependent on campaign contributions from corporations. It's not weird to think that some corporations act out of altruism, just like Ben & Jerry's often give campaign donations to Green New Deal politicians for reasons that are not per se related to their business, even if it might help boost their image. Other corporations are more of ''pay to play'' and expect that politicians return the favour.
There are bunch of examples of moderate politicians who are changing/altering their views (ideals) as they belief that accepting corporate money is the only pragmatic way to challenge the heavily funded Republicans. Congressman Richard Neal is one of those moderates who accept corporate donations, in this case from private equity and health care industry . He promotes himself as a guy who gets things done & beliefs in business friendly moderation that works for the average Joe/Jane. As head of the House Ways and Means Committee, he opposed a bipartisan bill to curb the practice of ''surprise'' medical billing, when health care providers outside of a hospital's insurance network spring exorbitant bills on unwitting patients. Basically, he is selling out patients for donors that fund his campaign.
Neal is not the only exception, as we already have seen in this threat with other moderates like Derek Kilmer (accepts donation from a mining corporation & consequently draws a bill that promotes commercial mining in space) & Andrew Cuomo (accepts donation from health care lobby groups and & gives immunity to nursing home executives). And the list goes on when it concerns moderate politicians who sell ideals for the sake of ''pragmatism''.
You're are not wrong in posing the argument that Progressives need to stick to their principles at all times, even if it concerns an endorsement of one individual. IMO Joe Rogan's endorsement should have been rejected by Bernie Sanders. I understand that he is a huge influencer and that he might be effective in convincing lots of people in supporting the Progressive cause, but his history is at odds with Progressive ideals & has slightly damaged the credibility of Bernie's campaign.
When it comes to ''terrible'' endorsements, the same goes for the DNC and the moderate Democratic leadership. They can finger-point all they want about progressive faux ''purism'', so why don't they start giving a good example themselves? The Democrats did not set a good example by accepting the endorsements of war hawks (such as Collin Powell), Anti-gay, anti-abortion & union busting conservatives (John Kasich), etc.
Like you, I hope that Progressives and Centrists find common ground somehow in how to tackle the troubles of our times, like global warming. A divided Democratic Party will only serve those who will make your country, and in broad sense our planet, not a better place to life in.
Link about Richard Neal:
https://www.huffpost.com/entry/rich...r-surprise-billing_n_5f4de7d6c5b64f17e1422adf