"The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants." -- Thomas Jefferson

It was not his finest moment. Jefferson was writing from Paris and referring not, as is commonly believed, to the French Revolution (which was yet two years off) but to Shays' Rebellion. Still, it reflected his views on the French Revolution as well, as he would later write, "Rather than it should have failed, I would have seen half the earth desolated.''

But while a tolerance for bloodshed in the name of liberty evokes a shudder, Jefferson's insight that the spirit of liberty needs refreshing from time to time does recommend itself -- and it is relevant to our current divisions over immigration.

I've been quiet on this debate because I find myself in the unfamiliar position of moderate. I cannot rejoice with so many of my conservative friends over the defeat of immigration reform, yet neither would I have been happy to see the legislation passed in the form it was offered. I don't think we have begun to deal properly with the immigration problem because I believe it implicates other questions, like those of education, welfare and national identity.

I persist in feeling well disposed toward those who wish to become Americans (particularly Catholics from Latin America, as I believe these are eminently assimilable populations), and I do fret that the Republican Party may have inflicted serious political damage on itself by appearing to be anti-immigrant. I have heard nothing to convince me that the illegal immigration problem is not a reflection of legal immigration quotas that are too low. We have a full employment economy and a poor neighbor to the south. Is it any shock that employers are loath to turn away willing workers or that impoverished people are streaming across the Rio Grande? Are these low-skilled workers? You bet. Do we need them? Arguably yes.

According to the National Center for Education Statistics, only about half of the population aged 25-29 in 1950 held a high school diploma. By 2000, the black high school graduation rate was 83.7 percent and the white rate was 91.8 percent. High school graduates tend not to seek agricultural, household, meatpacking or lawn work.

On the other hand, Robert Rector of the Heritage Foundation and others who point out the heavy demands immigrants place on the social welfare system are very persuasive. They argue that with the Earned Income Tax Credit, food stamps, education, health costs and other programs, each legal immigrant is actually a net drain on the public purse (and though few say so out loud, the obvious corollary is that illegals are actually a fiscal bargain, though this is hardly an argument for permitting widespread flouting of the law).

Honest advocates of the failed immigration law, like economist Diana Furchtgott-Roth of the Hudson Institute, acknowledge this and respond that we have a "welfare problem not an immigration problem."

I agree. But let's be realistic. What are the chances of passing welfare reform when the Republican Party is ailing? And what are the chances of passing an immigration reform that would deny to new immigrants access to welfare when the Democrats' criticism of the existing bill was that it was insufficiently generous?

What then of Jefferson? The greatest benefit of immigration by far is not what it does for the immigrant (though that is huge) but what it does for America -- assuring a steady stream of newcomers who do not take the blessings of liberty for granted but cherish them. Many opponents of immigration are worried about diluting our culture. I'm far more worried about the hollowing out from within. We scarcely teach our own children to love America, far less inculcate patriotism in immigrants.

If I were writing the law all by myself, I'd increase the legal immigration levels, beef up border enforcement, establish a national ID card so that we could really know who is here, and reform welfare so that only those who truly want to work would be tempted to immigrate. I'd also reform education to convey the greatness of this nation (warts and all). So here I am, in the awkward middle.