Dem
47
GOP
53
Donald Trump wants one beautiful giant bill with all his priorities in it. This strategy has two problems. First, the House margin is very tight. As soon as the two Florida representatives elected Tuesday are sworn in, the House will be 220R, 213D, with two vacancies in deep blue districts, one in Arizona and one in Texas. Both are required to be filled by special elections. See below for some information about the AZ-07 race. Gov. Greg Abbott (R-TX) has not scheduled a special election for the D+23 district of the late Sylvester Turner. He might just not bother, since that would cost the state of Texas money and he is keen on saving the taxpayers money. Until the end of September, Speaker Mike Johnson (R-LA) can afford to lose only three votes on a bill and with giant bills, there is always something for some Republican to dislike. That is problem #1.
Problem #2 is that Republicans want to use the budget reconciliation process to avoid a filibuster. Sen. Cory Booker (D-NJ) is already practicing in case he needs to filibuster again. But a bigger problem is Elizabeth MacDonough, the Senate parliamentarian since 2012. It is her job to make sure that all bills passed using reconciliation take a Byrd bath and come out clean. This means that they contain only items that are primarily budget related. A clean bill could contain more funding for the Border Patrol but it may not increase the punishment for entering the country illegally. That would have to be done through regular order.
Her decision is not final and the Senate can overrule MacDonough (or even fire her), but Majority Leader John Thune (R-SD) is an institutionalist and does not really want to break the Senate, so there is likely to be some horse trading with her. The problem is that Trump wants a lot of things that are not budget related in the bill and she is going to politely, but firmly, tell Thune that no, some things in the bill aren't allowed. This is going to slow down the process quite a bit—once there is a bill. So far, there is no concrete bill because members of the House can't agree with each other and members of the Senate can't agree with each other.
One big issue is the scoring model. The reconciliation process requires that bills passed using it not add to the deficit after 10 years. Determining whether the bill adds to the deficit after 10 years requires first determining what the deficit is now. Under current law, many of the 2017 tax cuts will expire this year. Should the baseline be the deficit as it is right now or as it will be when the 2017 tax cuts expire? When the tax cuts expire, the government will suddenly have much more revenue and the deficit will be "small(er)". If the baseline is a small deficit, then any new tax cuts will have to be offset by (painful) spending cuts. Republicans don't want to have to vote on that. They would prefer MacDonough say that the deficit is huge today, so they can cut taxes willy nilly and not increase the deficit over 10 years over the baseline. Democrats claim this is cheating and it has never been done this way. So MacDonough's decision will be critical. She is a straight shooter and just applies the Senate rules, but Republicans will be very unhappy if they don't like her decision. (V)