I don't know how we got here - on a liberal site such as this no less - that we think a moderate candidate is our best option. History has shown us time and time again that this is not true. The last moderate to win was Bill Clinton - and he got an assist from Perot. President Obama was indeed more moderate than candidate Obama was, but while he campaigned he won over progressive support by running on "Change" and having some progressive policy pieces. Without that progressive support, there's an extremely narrow path to victory.
Being opposed to “Trump the unknown” in 2016 was not enough to win. Being opposed to “Trump the impeached” in 2020 should be, but we still need a candidate that will inspire enough voters in all the right places to win this election. The consensus seems to be that only a moderate can win those battleground states, but Hillary lost half of them and a "leans Democrat" state (Michigan). Obama won all the battleground states both times. Obama was inspiring.
The media and the pundits and the Democratic establishment themselves insist that we choose a moderate. This they are sure of despite the undeniable fact that the 2016 Democratic candidate was a moderate and cost us the Presidency, winnable Senate seats and the House by 47 seats. Did Hillary have issues beyond just being a moderate? Of course she did - and so do all the moderates running this year. They all have less baggage than Hillary (except probably Bloomberg), but none are "better" than Hillary and none more inspiring.
Moderates are still blaming progressives for 2016 and refusing to acknowledge that they pushed the progressives out. Progressives were energized and motivated and fought 'til the end to get Bernie the nomination despite the deck being stacked against it. Afterward, a large majority of them voted unenthusiastically for Hillary - and then got blamed anyway for her loss.
2020 is unfolding the same way. Those who were wrong last time are once again telling progressives that their candidate isn't good enough (though they apparently can't come to a consensus on who is). Even Elizabeth Warren has been labeled too radical by many Democrats. The influential Democrats should be explaining to moderate voters how progressive policies will better their lives, but instead they argue that progressives just need to accept moderate policies. All Democrats should want a President that pushes for strong liberal policies, not one that starts at the centrist position and negotiates down from there. Progressives know that Congress will dictate that, but they still want to put the strongest fighter out there at President.
I've seen complaints that Bernie didn't move the needle enough in the Iowa and New Hampshire primaries to make people comfortable with a progressive revolution - despite the fact that he had the largest voter turnout in both states. They tell us we'll have a better chance if we nominate one of the losers of those primaries or maybe Bloomberg cause he's rich and has good ads. So yes, Bernie's numbers are down so far this year. Why? The progressive base may already be suppressed because of how things turned out in 2016. Everybody is desperately telling us not to vote for who we want to win but who they tell us is electable. Exit polls in NH (and Kos discussions) show that it definitely hurt Bernie's results - and yet he still won.
The reality of the situation is that progressives want Sanders. Progressives would probably turn out good enough numbers for Warren too (she at least has some progressive policies). But I assure you that a moderate candidate will negatively impact voter enthusiasm and weaken turnout again - especially younger voters. If moderates can't shift to the left we're in for 4 more years of Trump. My advice to the "Bernie will cost us everything" crowd is to coalesce around Warren before it's too late. I agree with Kos that she can appeal to the largest group - getting enough progressive and moderate support. But Bernie is staying in this thing to the end, and a contested convention is possible.
If your first thought for the reply is "If progressives can't tell the difference between Trump and Klobucher/Bloomberg/Biden/Buttigieg then we're screwed" then maybe it should occur to you that moderates had better be ready to vote for Sanders/Warren over Trump. If you're telling me that the moderates are actually the "vote my way or the highway" crowd, then the progressives have really gotten a bad rap these past few years.
How many losses do moderate candidates need to hand us (Mondale, Dukakis, Gore with friggen Lieberman, Kerry, Hillary) before we stop pushing the false narrative that they are our better option? I've lost track of the number of McGovern references I've seen on this website. That was 48 years ago - when only 15% of the current population was even old enough to vote. That was literally a lifetime ago. It's time to move forward. If we choose a moderate there's a very good chance Trump takes us back another couple decades - where McGovern would be relevant again.
P.S. I voted for Hillary and voted for Blue Dog Ben McAdams and I'll vote blue this year as well (I'm pragmatic) - but my primary vote goes to Bernie again.