WASHINGTON – Leaving President Bush’s proposed immigration overhaul in disarray, Republicans on Friday won congressional approval for fencing nearly one-third of the Southwest border and prepared to head into the November elections with a tough border security message.

Rushing to finish work before leaving on a six-week campaign recess, the Senate passed, by a vote of 80-19, and sent to President Bush a bill for more than 700 miles of fencing. The House approved the bill in mid-September.

The legislation – which Bush has agreed to sign – was denounced by critics as little more than a symbolic gesture by Republicans to appeal for votes in their re-election campaigns. But GOP supporters hailed the fence as the cornerstone of a legislative offensive to plug the porous 2,000-mile border with Mexico.

“It’s important that we demonstrate to the American people that we are serious about securing our border,” said Sen. Jon Kyl, R-Ariz., “and it can’t be done without the fence.”

The proposed construction of the five-section fence – along with roads and vehicle barriers – has threatened to tarnish diplomatic relations with Mexico and has prompted resolutions of opposition from several U.S. towns along the border. Outgoing Mexican President Vicente

Fox has condemned it as “shameful.”

The largest section of fencing would reach 361 miles from Calexico, Calif., to Douglas, Ariz.

Three sections would be in Texas – a 51-mile stretch from Del Rio to Eagle Pass; 176 miles from Laredo to Brownsville and 88 miles stretching westward to Columbus, N.M.

A 22-mile section would be built near San Diego, Calif.

Texas’ two Republican senators, Kay Bailey Hutchison and John Cornyn, both expressed reservations with the House-passed bill, saying it was not Congress’ role to tell states where the fences should be built.

Hutchison had hoped to offer an amendment that would have allowed the Department of Homeland Security to determine location and need for border fencing after consulting with state and local officials.

But Senate leaders decided not to allow amendments to avoid sending the measure back to the House, where it would have likely been rejected.

House and Senate leaders assured Hutchison that they would allow modifications to accommodate her concerns after lawmakers return for a so-called “lame-duck” session after the elections.

Bush has vowed to keep pushing Congress for enactment of an immigration package that includes a temporary guest worker program and legal status for millions of undocumented immigrants after they meet certain requirements. But with time running out before the 109th Congress adjourns by the end of the year, the prospects of a breakthrough seem unlikely.

“We’ve abandoned principles and allowed politics to triumph,” said Sen. Ken Salazar, D-Colo., calling the fence a “political gimmick.”

The Senate passed a comprehensive bill in May that embraced the key elements of Bush’s immigration plan, including a guest worker plan and a three-tier program that would have put most of the more than 11 million illegal immigrants on a path to U.S. citizenship. But the plan was shelved in a stalemate with the House, which passed a strikingly different immigration bill focusing primarily on enforcement.

The fence was the most high-profile element of a late-breaking package of border security initiatives unveiled by House leaders following a series of summertime field hearings. Several other pieces of the package, including a bill empowering local officers to enforce immigration laws, have thus far stalled in the Senate.

Supporters of the fence say it will complement an initiative by the Department of Homeland Security to erect a “virtual wall” that includes an array of high-tech gadgetry, including sensors, cameras, radar and unmanned aerial drones. The department has awarded the contract to a team led by Boeing Corp.