In the real world, the House passed a version of the CR that wasn't supported by a majority of the House Democrats. An amended version was submitted by Mikulski for consideration by the Senate on March 11 that included over 200 additional pages of provisions, including the Monsanto provision. Tester and six other Democrats submitted an amendment to strip that provision, but like the overwhelming majority of amendments submitted, they did not make the cut when the Senate leadership worked out a time agreement for debating the CR. When the bill was voted on in the Senate every Democrat voted for it except Tester. In other words, the six Senators that had joined him in proposing an amendment to strip the Monsanto language still voted for the CR even though that language remained in the bill. The bill then went to the House where, in a turnaround from the vote on the original version, a majority of Democrats supported its passage.
So, in order to get a "clean" CR, the president would have to veto the bill and then hope than enough Democrats would reverse their position and vote to sustain the veto. Yet, that had zero chance of happening. If six out of seven Senators who were on record as opposing the Monsanto language still voted for the bill the first time around, they weren't going to switch and put the funding of the government at risk after a presidential veto. Nor would other Senators. It would make it look like the President and the Democrats were in complete disarray and were putting the funding of the government at risk over something that members had previously voted for.