Collectively, the engagement underscores the degree to which both the White House and its allies are worried that the administration’s request — or at least something resembling it — won’t make it through Congress quickly. And it reflects the hurdles that come with divided government, in which intense opposition among a segment of House conservatives, and a smaller subset in the Senate, can quickly complicate a top agenda item for the president. Biden aides remain confident Congress will pass an aid bill even as they concede that the legislative process means any final version won’t exactly match their request. A...