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.
Such a bill might have a better chance of being enacted. It would offer a better chance of enforcement actually taking place.
Supporters of the current approach would have a better shot at getting the amnesty they want. And Silicon Valley would have a better chance of getting the high-tech workers it seeks.
To make such an alternative a reality, opponents of the current Senate bill have to hold firm and keep anything like it from passing the House. Having then failed for a third time with this approach, supporters of the bill might be willing to try a new one.
But opponents would have to do something else, too: Accept a limited amnesty now and a bigger one later.
Some House Republicans would surely balk, thinking that any amnesty is a retreat from the rule of law and that there is no demand for such a package of reforms in their districts.
Other Republicans, though, oppose the Senate bill for different reasons.
They don't think that every illegal immigrant already here should be deported or have to live in fear of it; they just don't want today's amnesty to lead to tomorrow's.
They appreciate that bending on this issue could improve their image nationally, especially among Hispanics, and make it more likely that they will someday have a Republican Senate and president to work with; they're just not willing to pass bad legislation for this political purpose.
Polls suggest that the public favors tougher enforcement, is open to amnesty for some undocumented immigrants, and opposes major increases in immigration.
The public seems to me to have the right instincts on all these matters, and it can get what it wants if Congress writes a new bill.
Ponnuru, a senior editor at National Review and a visiting fellow at the American Enterprise Institute, is a Bloomberg View columnist.