By your logic - we could avoid ISIS attacks - by just recognizing their Caliphate.
Neither Pelosi nor Shumer is under any obligation to pursue Trump's agenda. And that goes double for an unpopular part of that agenda - that he couldn't get passed, when he had a majority in both houses of Congress.
They ran against Trump and his wall - and have a duty to their constituents to deliver on THEIR agenda - not his. He had a duty to deliver on his campaign promises (including getting Mexico to pay for his wall) during the time when he had a legislative majority. So his failure to deliver is on HIM, and Paul Ryan and Mitch McConnell - not Chuck and Nancy.
A better politician, with some experience, would know how to get things done... By doing some horse-trading. For example: AOC's proposal for a top marginal tax rate of 70% - only upon portions of income over a $10 million threshhold - is MAJORITY POPULAR... If he wasn't an idiotic demagogue (and an enormously racist/xenophobic asshole), being managed by Far-Right ideologues - he might offer to work that into the tax code - in return for the first 5 Billion generated, going to his stupid wall... He would be outflanking Pelosi and Shumer, in a populist fashion - from both sides simultaneously. But alas ... He comes from a private corporate environment - characterized by enacting policies, based upon his autocratic fiat, without even so much as an independent board of directors, or shareholders, to answer-to.
As for a vow - to oppose Trump at every turn - please provide some evidence of this. It sounds like you're confusing the vow of obstruction that Mitch McConnell, and the GOP leadership in Congress swore - at a well reported upon meeting, early on, under Obama.
You show all the lack of empathy for hard working Americans (in these defenses of the Trump Shutdown/ Hostage taking of the Government) that the GOP is famous for, amongst those who are paying attention (so clearly, not their "low-information voter" base). The companies that those contractors work for - were shut down through no fault of anyone but Trump and McConnell... It was nothing that their management or workers could anticipate, plan for, or change... And yet they were forced to bear the costs, and shoulder the burden for a callous billionaire, pursuing an unreasonable strategy, to achieve an unpopular policy... That is the very definition of - "out-of-touch, with the American people" - but "in touch" with the far-right, neo-nazis and KKK.