Sen. Chuck Hagel played a valuable and potentially historic role in helping his colleagues put together a comprehensive immigration reform bill that tackles all of the necessary issues.

His work on immigration reform has been constructive and responsible.

Sen. Ben Nelson, on the other side of the aisle, seems more concerned about how the issue could be used in his campaign battle with challenger Pete Ricketts.

It’s with considerable wonderment that we watched Nelson join with the jeering throng far to the right of President Bush in calling the Senate legislation an “amnesty plan.”

That’s an unfair characterization of the legislation introduced and shaped by Hagel and Sen. Mel Martinez, R-Fla., that won 62-36 approval in the Senate.

First, the Senate bill takes the necessary first step of closing the border to the flood of illegal immigrants.

The bill calls for constructing hundreds of miles of new fence at the Mexican border and building 20 new detention facilities. It calls for doubling the number of border patrol agents to more than 25,000, with a 70 percent increase in the number of immigration and customs enforcement officers.

In that sense, the Senate legislation is similar to the one-dimensional bill that passed the House earlier this year, which focused too exclusively on border security.

Hagel’s bill also would increase maximum fines to employers for hiring illegal workers to $20,000 for each worker and impose up to three years of jail. It would require immigrants and guest workers to show a machine-readable, tamper-resistant identification card that includes a digital photograph of the individual and would establish an employee electronic verification system to verify that newly hired employees are legal.

But the Senate bill, thanks to Hagel’s work, takes a pragmatic approach to the dilemma created by the estimated 10 million to 12 million immigrants already in the country illegally.

It would create a guest worker program and a path to citizenship. For example, an undocumented immigrant who has been in the United States five years or more would have to pay a $3,250 fine and back taxes, pass national security and criminal background checks, prove he or she has worked for at least three years, register for military service and demonstrate knowledge of English and U.S. civics. All other undocumented immigrants would have to leave the country and re-enter legally.

The bill is a major improvement on the crude and incomplete effort passed by the House earlier this year. If House conferees are sincere about trying to actually trying to solve America’s problem with illegal immigrants, the final compromise bill should retain the basic elements of Hagel’s plan. To correct decades of failed immigration policy, Congress can’t leave the job half done.