They’re doing it, we are told, to get to 70 votes. But why is that an important goal? By what logic would it make a Republican member of the House more likely to vote for the bill? A 70 vote margin made up of all 54 Senate Democrats and 16 of the chamber’s 46 Republicans isn’t going to move a lot of House Republicans. Surely the number of votes doesn’t amount to a substantive argument for the bill, and as a political argument I don’t see why the prospect of aligning with Senate Democrats against nearly two thirds of the Senate Republicans would be appealing to a skeptical House member.

The more likely message that a larger Senate margin would send to the House is that there is a lot of room for changes in the bill. A cushion of 10 votes would suggest that the bill could move some distance to the right without losing its chances of passage in the Senate. Revisions (or a different bill) with a more conservative approach to border security, the legalization process, legal immigration levels, or whatever else might draw more House Republicans could appeal (for the same reasons) to Senate Republicans who oppose the current Gang of Eight bill while not turning off all the Democrats. If the Gang of Eight bill gets 70 votes, a revised House version that, on its return to the Senate, could get 15 or 20 more Senate Republicans on board could afford to lose 25 or 30 Senate Democrats and still pass the Senate (assuming it got a vote). A larger Senate majority makes House passage (or even consideration) of an unamended Senate bill even less likely, not more. That at least is the lesson suggested by the budget battles of the last few years (and of much House-Senate history besides).