Now that the Senate is taking an honest look at the immigration problem, it's time for the rest of America to be honest about what the problem really is.

Much of it really is about clashing cultures and a concern that immigrants aren't assimilating. When someone complains that San Diego is "becoming like Tijuana," or when someone else says — as an Idaho woman recently told the Los Angeles Times — that her neighborhood has become a Spanish-speaking "shantytown," it's a dead giveaway that, for many Americans, the problem is not with people coming into the country illegally, but with the effect they have on their surroundings once here.

This week's student walkouts, in protest of efforts to control illegal immigration, brought this sentiment to light. When more than 25,000 students in Los Angeles, and thousands of young people in other cities, took to the streets, what enraged many observers — judging from talk radio and television shows — was that the protesters waved Mexican flags.

This reaction is no surprise. This country of immigrants has never been welcoming of new immigrants, even those who came legally.

So why don't these people save us all a lot of time and admit that they don't like immigrants and don't really care how the immigrants got here? Sure, they might come across as nativist and narrow-minded, but they wouldn't be alone.

Rep. Tom Tancredo, R-Colo., proposed a moratorium on legal immigration and a revision of the H-1B visa program aimed at high-tech workers. Dan Stein, president of the Federation for American Immigration Reform, has called for a "timeout" on immigration — both legal and illegal. Mark Krikorian, executive director of the Center for Immigration Studies, has said that he'd limit the number of legal immigrants to just 300,000 per year — about a third of what it is currently — and create a system where we'd take in only the spouses and adopted children of U.S. citizens.

Bad ideas one and all.

Most Republicans in Congress insist they're not anti-immigrant. If that's the case, the time has come to prove it by allowing higher levels of legal immigration.

It's only fair. They and their political posse have insisted all along that — in what has become a convenient sound bite — they aren't anti-immigrant, only anti-illegal immigration.

In fact, CNN's Lou Dobbs said exactly that on his show recently in response to viewer mail that accused him of being anti-immigrant.

Personally, I think Dobbs is pro-ratings. And the fact that ratings for his show are up since he seized on the immigration issue proves that it's not only employers that prosper thanks to illegal immigrants. The same is true of aging television commentators.

And yet, on the question of whether we should maintain or increase current levels of legal immigration, Dobbs has been uncharacteristically silent.

Not so the Senate Judiciary Committee, which this week produced a reform bill that, among other things, increases the number of visas allocated to legal immigrants.

The same is true of the competing bill proposed by Senate Majority Leader Bill Frist. The Frist bill would more than double the number of employment-based green cards, from 140,000 to 290,000, and make more work visas available to unskilled workers. It also would make room for more legal immigrants by exempting immediate relatives of U.S. citizens from the annual allotment of visas, and increase the limits on relative-sponsored and high-skilled immigrants.

For those who believe, as I do, that legal immigrants are one of the best things about this country, and that they bring vitality and optimism and fresh blood, these reforms are just good common sense.

But for those restrictionists who don't like immigrants, regardless of how they get here, the proposals are cause for alarm.

Among the alarmed is conservative activist and anti-immigrant opportunist Angela "Bay" Buchanan. She told CNN that the Frist bill was "worse than McCain-Kennedy," the measure that forms the basis for what the Judiciary Committee produced.

What seems to worry Buchanan is that we'd still be bringing in all these immigrants — legal sure, but still foreigners with their different languages and their strange religions.

Funny. That's pretty much what Sen. Henry Cabot Lodge of Massachusetts was worried about in 1905 when he called for immigration restrictions because of the effect that foreigners from countries such as Ireland were having on "the quality of our citizenship" — people that might well have included an earlier generation of the Buchanan clan.