Amazon workers on Staten Island vote to unionize

In the US a union is tied to a workplace. A single company, often a single location. This is by design of the NLRA.

Corporations fight to limit the size of the bargaining unit, to make the unions less powerful. This Amazon warehouse is unionized, but the other warehouses are not unionized and warehouses over a FooBar Corp. are not unionized. Each of these unions has to work out their own contract and bargain independently even if they all work for the same company.

This gives the workers less leverage and makes it easier for US Corps to pit workers against each other.

In Germany and elsewhere in Europe, unions are also organized by sector. You could have a national Warehouse workers union, which sets working conditions for all warehouse workers. This gives them significantly more leverage and makes it difficult to do the kind of "we shut down this store and open another" tactic that you see in the US.

I'm sure there's a variety of other differences, but I don't think it's fair to characterize EU unions are weaker.

The right are proponents of right-to-work legislation that force unions to represent non-dues paying members for free, and nullifies their private contracts. That's not exactly liberty, and it minimizes risk for owners.

Because the Republican party tends to line up with rural voters, they have a statistical advantage in both the Senate and the Electoral College; because of gerrymandering, they actually have a statistical advantage in most House races, too. (That last one is more complicated, but the short version is that when Democrats are in charge of redistricting they tend to favor putting nonpartisan committees in charge of drawing district lines, while when Republicans are in charge of redistricting they tend to favor drawing the lines themselves for partisan advantage.)

The upshot of that means that Republicans can and do win elections by appealing to their most partisan voters, but Democrats literally can't do that. Republicans can get rid of moderate Republicans and still win enough elections to maintain or even gain power; Democrats cannot get rid of moderate Democrats and get the same result.

So, actually, no, the Democrats can't "block, blacklist, and crush" campaigns of moderate members. They can do that to progressives in districts that are still swing districts, whose voters seem to be largely centrist. Maybe that's good, maybe that's bad, but statistically speaking, when centrist Democrats run in those swing districts they win more often than progressive Democrats do. Joe Manchin is not from a swing state; he's from a state that went for Trump by 35 points in 2020. He's a fluke, and if he loses his seat, he ain't gonna be replaced by someone who votes with Democrats nearly as often as he does -- which is, IIRC, about 70% of the time. This is something else that often gets lost: the truth is that the most conservative Democrat still votes with Democrats a majority of the time, just like the most liberal Republican still votes with Republicans a majority of the time.

Maybe this balance will change; maybe it'll change sooner rather than later. But there seems to be this pervasive idea on the Left that Democrats would be able to pass all the legislation they wanted if they just had enough strength or willpower or something, and that just isn't true, no matter how much we might wish otherwise. If you only have 51 people on your side, counting the VP, and a single one of them is determined to keep the filibuster, then you're going to keep the filibuster. There is no amount of pressure you can put on that person that's meaningful, because you will need them on your side for other battles, they know it, and you know it. And if you keep the filibuster and there is no way you will peel 10 people off from the other side no matter what the bill is, you're not going to pass anything that can't get around the filibuster. Period. Full stop.

Those union members are perfectly free to create was is called a members only union, which only represents its own members who voluntarily join the organization.

Doing that avoids any of those conditions that you are talking about.