Neoliberalism and incremental change isn't the way America should move forward in my view. You can't win an election on a Trump is a bad platform. The Democrats clearly need someone who can win the midwest (Ohio, Michigan, Wisconsin, etc). I think about 9% of Obama voters voted for Trump last election, so it's about getting those people back on side. The best way to do that is how Trump did it, through a populist message which yes, is what Bernie, AOC are pushing. People are already calling Bernie socialist and it isn't slowing him down. He is beating Trump head to head in the polls and is up 5 points on Joe Biden (even though the poll was comprised of 61% Hillary voters in 2016 primary and 35% Bernie voters).
And screaming about the Mueller Report and thinking it will get you a victory is clearly idiotic when you could focus on issues which will actually improve quality of life, reduce poverty, income inequality (which is extraordinarily high). This is why Bernie and AOC are the clear way forward if the Democrats want to win consistently and comfortably, by winning over working people.