Let’s start with the actual results in the 2016 primary. It was not remotely close. Sanders lost by 3.8 million votes, 57-43%. She won 34 states and territories to his 23.
… Sanders lost to Clinton by more than 200,000 votes in the nine states of the Midwest. In the three onetime Blue Wall battleground states, she topped him by over 45,000 votes, though he beat her in Wisconsin and edged her by a point in Michigan. In Ohio, Clinton won by 14 points and nearly 166,000 votes. The best you can say about this Sanders argument is that he didn’t lose as badly in the Midwest as he did elsewhere.
Indeed, in the Sunbelt, the other area that Democrats hope to make a general election battleground in 2020, Sanders got absolutely crushed. He lost Florida 64-33%, Arizona 58-40%, North Carolina 55-41% and Texas 65-33%. Taken together, Clinton trounced Sanders in those four states by more than 1.2 million votes.
…On the very day in 2017 that The New York Times published an op-ed he wrote entitled, “How Democrats Can Stop Losing Elections,” his favored candidate in the Virginia gubernatorial primary got blown out by moderate Ralph Northam, who went on to trounce the Republican in the general election.
In 2018, Sanders waded into the Michigan governor’s race and backed Abdul El-Sayed, a young, far-left candidate. El-Sayed lost every county in the state to the more mainstream Gretchen Whitmer. She went on to soundly beat the Republican by promising not a “revolution” but rather to “fix the damn roads.”
This pattern repeated itself throughout the country. Sanders and his political organization backed candidates at every level, to little or no avail. Their endorsees did not flip House seats from red to blue in 2018, proving that his ideas work only in safely Democratic places.
…In the past, when Bernie Sanders has declared himself and his ideas to be “winners” in red and purple areas, it has turned out to be demonstrably false.