The Senate overwhelmingly passed a complicated immigration bill that would simultaneously shore up border security and grant amnesty to millions of illegal aliens already in the country. This will lead to a contentious showdown with the House of Representatives.

Charles Babbington on WaPo’s A1:

The Senate yesterday approved legislation that would trigger the biggest changes to U.S. immigration policy in decades, by strengthening border security, establishing a guest-worker program, and providing the means for millions of illegal immigrants to stay in the country and possibly become citizens.

The product of a tenuous bipartisan coalition that faced tough conservative opposition, the measure calls for 370 miles of triple-layer fencing along the Mexican border, a complicated three-tiered system for determining who can stay and who must leave the country, and more jail cells for those awaiting deportation. It would declare English the country’s national language, a gesture that many advocates found insulting but accepted in hopes of helping millions of undocumented workers achieve legal status.

But even as the Senate approved the bill 62 to 36, the measure’s backers acknowledged that it faces formidable opposition in the House, whose political dynamics differ markedly from the Senate’s. Numerous House members insist that Congress do nothing about legalizing immigrants until illegal border crossings are dramatically reduced.

Democrats and Republicans alike said a House-Senate accord will be nearly impossible without the vigorous involvement of President Bush, who favors an approach similar to the Senate’s. The White House has already begun lobbying efforts, but it faces resistance from more than 200 House Republicans seeking reelection this fall, many in districts where the sentiment against illegal immigrants runs high.

Rachel Swarns for the NYT adds:

But the bill’s path from here leads straight into a deep divide among Republicans, with conservatives in the House suggesting that they will not support any compromise that includes a central provision of the Senate bill, its call to give most illegal immigrants a chance to become citizens. They have vowed to fight to prevent such legislation from becoming law, and they have the support of many grass-roots conservatives around the country.

Representative John A. Boehner of Ohio, the House majority leader, said today that he was hopeful that the Senate and House could reach a compromise. But when asked what form that compromise would take, he acknowledged he did not know. “This is a very difficult issue,” Mr. Boehner said. “We have two very separate and distinct directions that we’re going when it comes to controlling our borders, enforcing our laws. I don’t underestimate the difficulty of the House and Senate trying to come together in an agreement.”

Conservatives in the House said they did not intend to budge. But moderates in the House countered that they believe the ground is shifting, even if slightly. They pointed to Representative Mike Pence, Republican of Indiana, the leader of the conservative caucus in the House, who proposed a bill this week that would allow illegal immigrants to become guest workers, although they would not be allowed to become permanent residents or citizens. They also pointed to Mr. Bush’s aggressive push for a deal that would include a temporary worker program and a path to citizenship for illegal immigrants. And they noted the sizeable numbers of Senate Republicans including the Senate majority leader, Bill Frist of Tennessee, who offered vigorous support for the legislation.

All of those developments, they said, might provide enough political cover for some anxious Republicans to sign on to a plan for a plan that might include a temporary worker program. Representative Jeff Flake, an Arizona Republican and a supporter of legalizing illegal immigrants, said that a week ago he was betting that the House and the Senate would not even be able to agree on a meeting. Now, he says he describes the chances of a House-Senate compromise bill as “50-50.” “I think the dynamics are changing,” Mr. Flake said. “The ball’s back in our court. We have to move.”

[…]

In an effort to reassure conservatives, administration officials also moved swiftly to make good on their promise to reinforce beleaguered Border Patrol agents, telling the House Armed Services Committee that the first contingent of up to 6,000 National Guard troops would be deployed to the border with Mexico on June 1.

[…]

Under the Senate agreement, illegal immigrants who have lived in the United States for five years or more, about seven million people, would eventually be granted citizenship if they remained employed, passed background checks, paid fines and back taxes, and enrolled in English classes. Illegal immigrants who have lived here two to five years, about three million people, would have to leave the country briefly and receive a temporary work visa before returning, as a guest worker. Over time, they would be allowed to apply for permanent residency and ultimately citizenship. Illegal immigrants who have been here less than two years, about one million people, would be required to leave the country altogether. They could apply for the guest worker program, but they would not be guaranteed acceptance in it.

The legislation would also require employers to use a new employment verification system that would distinguish between legal and illegal workers. In addition, it would impose stiff fines for violations by employers, create legal-immigrant documents resistant to counterfeiting, increase the number of Border Patrol agents and mandate other enforcement measures.

As I told Tammy Bruce when we were discussing this issue recently, this is the natural dynamic of House-Senate interaction. The Framers intended for the Senate to take the longer view and the House to be more influenced by the passions of the day. We’ll see which prevails in this case. There are few issues that generate more heat than this one.