The bill’s guest-worker programs subvert civic ideals by creating a large class of people who work here but can’t be full participants in American life. Its provisions against illegal immigration are weak — the Congressional Budget Office’s most optimistic take suggests the bill would reduce future levels by only half — and there is reason to think they will be set aside as previous enforcement promises have been…

The danger of a more sweeping amnesty is that it would encourage new illegal entrants by signaling that they will eventually be legalized, too. Congress should therefore hold off on that step while making sure that enforcement is up and running — and that the political forces that are supportive of amnesty have an incentive to make enforcement work rather than subvert it. Limited amnesty would be a good-faith gesture to show that the promise of future legalization isn’t merely words.

An alternative should also take a different approach on legal immigration. It should encourage immigration by highly skilled individuals, especially scientists and engineers, for the sake of higher economic growth. It should at the same time cut back on immigration based on reuniting extended families, which is nice but shouldn’t be a national priority. In fact, we should stop reuniting adult siblings altogether until we have brought in the backlog of spouses and children of legal residents.

And, finally, the alternative shouldn’t include a guest-worker program. We don’t need to import a helot class.