Have they every REALLY put any ooomph behind it?

Yes. This was a priority of the Obama Administration, and Schumer put a lot of political capital behind it. Because the filibuster exists, these proposals always have to start with Republicans being on board. That's why none of the serious proposals start off as an "everything that Democrats want and nothing else" bill - it's a waste of everyone's time, since the Democrats invariably need at least a handful of GOP votes.

That's why I say they're going to have to spend political capital and do some dealing.

Again, they have done so in the past. But sometimes there's no deal to be had. A very large chunk of the GOP base has been unequivocally opposed to a pathway to citizenship, so there's no "deal space" for such a proposal. That's even more the case today, and it would be impossible to get a bill that included a pathway for citizenship through the Senate today, no matter what else it contained.

LOL. 1, it isn't up to these local jurisdictions to dictate federal policy. Every time they do, a judge reminds them to stay in their lanes:

Not every time. Sanctuary policies in general aren't new, and they've held up in court. State and local governments can't be "commandeered" into enforcing or administering federal law. So while they can't take any steps to prevent the federal agencies from doing their jobs, they are perfectly free to refrain from doing anything to help.

U.S. Congress: Browse Essay Amdt10 4 2