The latest developent in the long, painful saga of the Senate's consideration of immigration legislation is the decision by Republican backers of the bill (presumably with White House support and at least grudging acceptance from some Democrats) to sponsor an amendment expanding the "touchback" requirement for illegal immigrants who want a "guest worker" visa. In the original "grand bargain," illegals would only have to go home to their country of origin when their visa expired, or in order to apply for permanent legal status (i.e., to get on the "path to citizenship"). Under the amendment, they'd have to go home to apply for the guest worker visa.

This so-called "touchback" provision, dumb as it is (it virtually guarantees a low rate of compliance), is intended to scratch the conservative itch that I described yesterday as representing a neurotic legalism. In effect, it would demonstrate that the U.S. could deport all illegal immigrants (which is what large elements of the Right really want) if it chose to do so. More to the point, the amendment is yet another bone tossed to conservative Senators who are beginning to line up against the whole enterprise. With key procedural votes set for today and Thursday, that's become a monomaniacal preccuption for the bill's sponsors.

Obscured by all these placate-the-nativists maneuvers is the growing unhappiness of Democrats with where the bill seems headed. As the New York Times noted today, the labor movement is already split on the legislation, with the AFL-CIO formally opposing it, while three big unions in the Change to Win coalition (SEIU, UNITE HERE, and the farm workers) are backing it.

More broadly, Democrats are restless about the implications of voting for an increasingly bad bill "to keep the process going," counting on the House to pass something more acceptable. Nose-holding votes of this sort are standard fare in Washington, but so too is the fear that if the whole process breaks down at some point, Democratic Senators will be saddled with support for a legislative product that no one much likes.

If, of course, the "touchback" amendment and other concessions to the Right fail, and the whole unseemly "bargain" unravels, Democrats can and should gleefully hold Republicans accountable for the failure; the House could still proceed with something more sensible, though it would be largely symbolic. But if the Senate bill somehow survives this week, the "touchback" amendment may start to resemble a "turnover" of immigration reform to those conservatives who really want nothing more than to roll back immigration generally.