The Democrats are no more serious about border security today than they were when they falsely promised Ronald Reagan in 1986 that they'd secure the border in exchange for amnesty for some 3 million illegal immigrants.
Democrats are experts at seducing Republicans into abandoning their principled commitments. Over and over again, in contentious political skirmishes, Republicans relent in good faith — after accepting the Democrats' promise to deliver on their side of the bargain in the future — and immediately deliver their side. But that future never comes. In legal parlance, this is fraud in the inducement.
In his notorious "read my lips" travesty in 1988, President George H.W. Bush promised that if he were to be elected, there would be "no new taxes," but in 1990, he reneged on his pledge in reliance on the Democrats' disingenuous and later broken promise to cut spending.
Now the unctuous, cadaverous duo of Senate Minority Leader Chuck Schumer and House Speaker Nancy Pelosi demand that President Trump immediately reopen the federal government in exchange for their vague assurance that they will work with him in the future on border security measures.