In New York the Democratic Party's chairman is pushing forward a bill that would make it more difficult for third parties to get candidates on the ballot.

This proposal comes from, of all places, a commission meant to improve our democracy. But attacking the @NYWFP is deeply undemocratic—and it will only benefit Republicans. No Democrat should allow this to pass. https://t.co/0uScG5T2Ll

— Elizabeth Warren (@ewarren) October 29, 2019

The Democrats are doing this undemocratic thing that ironically would weaken minor parties backed by progressive Democrats and strengthen the state’s Conservative Party, which often cross-endorses Republicans.
The Conservative Party, unlike the progressive parties have enough voters to meet the threshold.

On the other side of the country, the Democratic Party-dominated states of California and Washington changed to a “top two primary” or a “jungle primary”.

The top-two systems used in California and Washington have again barred all minor party candidates from the November ballot, except the minor party candidates who ran in races with only one major party candidate on the ballot. “Major party candidate” in this context means a Democrat or a Republican.

In 2016 in California there were fourteen minor party candidates on a primary ballot: nine Libertarians, two Greens, two Peace & Freedom, and one American Independent Party.
Only five advanced to the November ballot because only one major party candidate opposed them. They were all right-wing Libertarians.
In 2016 in Washington there were thirty-three minor party candidates on a primary ballot: 29 Libertarians, one Green, one Socialist Workers, one Fifth Republic Party, and one Citizens Party.
Only eleven advanced to the November ballot because only one major party candidate opposed them. They were all right-wing Libertarians.

Are you starting to see a pattern?
There's more. The Republican Party-dominated state of Texas is looking to change the election rules.

Texas House Bill 2504, passed along party lines by the state’s Republican-controlled Legislature in May and signed into law by Republican Gov. Greg Abbott in June, lowers the threshold that minor political parties — defined in the law as parties that nominate by convention, as opposed to by primary — must meet to have their candidates appear on the ballot.

Under the new law, a third party’s candidates can qualify to appear on the ballot if any one of them got 2 percent of the vote in a statewide race in the last five elections. Previously, a third party’s candidates earned a spot on the ballot if any one of them won 5 percent of the vote in any of the most recent statewide elections.

Obviously Republicans have no problem with third parties, eventhough the right-wing Libertarians get roughly three times the number of votes that the left-wing Greens get.
Meanwhile the Democrats are so desperate to crush left-wing third parties that they are willing to boost right-wing parties. That seems counter-intuitive when you look at the overall voting population.

At face value this makes no sense.
More people identify with the Democrats on the left than with Republicans on the right, so Republicans have less margin for error.
Plus right-wing third parties are massively larger.

All things being equal, it's the GOP that should hate and fear third-parties, while the Democrats should welcome them laughing.
Instead the Dems are willing to viciously smear one of their own if there is even a baseless rumor about someone making a third party run.

The math doesn't add up. People aren't acting like the way the facts are being reported.
So the only logical conclusion is that a basic premise is flawed.

Using Occam's Razor, the flawed basic premise here is that the Democrats are on the left.

The reality is that no one is on the left.
However, Democrats pretend they are on the left in order to collect those votes.
That's why the Dems are so terrified of a challenge from the left, because it will expose the lie by showing the people what a real leftist party looks like.

Meanwhile, the Repubs actually are on the right, so they don't feel threatened by a challenge from the right.

If this isn't true then how come Dems keep telling their base "No, you can't have that!"

When you add it all up, the Democrats do more damage to the left-wing than the Republicans could ever do.