WASHINGTON (AP) — In his final acts of clemency, President George W. Bush on Monday granted early prison releases to two former U.S. Border Patrol agents whose convictions for shooting a Mexican drug dealer fueled the national debate over illegal immigration.

Bush, responding to heavy pressure from Republican and Democratic lawmakers alike, commuted the prison sentences of Ignacio Ramos and Jose Compean. The two guards from El Paso, Texas, each were sentenced to more than 10 years for the shooting, which they tried to cover up. They will be released within two months.

Opposition to their convictions, sentencing and firings has simmered ever since the shooting occurred in 2005.

‘‘After four years of fighting this, it’s taken a toll on me and my daughter, and really the whole family,’’ said Joe Loya, Ramos’ father-in law, who has received tens of thousands of supportive e-mails and spent much of the past two years traveling the country to speak about the case. ‘‘We wouldn’t give up. ... I knew sooner or later God would come through — that finally it would happen.’’

He said his daughter, Monica Ramos, called from New York after learning the news that her husband soon would be released from a federal prison just outside Phoenix.

‘‘She could hardly speak,’’ Loya said.

The border agents’ case became a rallying cause for conservatives concerned about border protection. On talk shows, people sympathetic with the agents argued that the men were just doing their jobs, defending the U.S.-Mexico border against criminals.

Bob Baskett, Compean’s attorney in Dallas, cited widespread congressional support from the bipartisan congressional delegation from Texas. ‘‘I think the president did the right thing,’’ he said. ‘‘An awful lot of people did an awful lot of work to get this done.’’

David Botsford, a lawyer for Ramos in Austin, Texas, said he had been guardedly optimistic that the commutations would be granted because of the support from Congress and the thousands of people who had sent letters of concern. The president has shown ‘‘he’s a compassionate man,’’ Botsford said.

Rep. John Culberson, R-Texas, who called the agents’ convictions a ‘‘grotesque injustice,’’ said he and other lawmakers initially had hoped to have the agents pardoned. ‘‘When it became evident there was resistance at the White House to a pardon, that’s when we shifted gears to ask for a commutation,’’ he said.

Culberson helped gather signatures from 31 of the 34 current members of the Texas congressional delegation and two former delegation members for a letter asking Bush for the commutations. Culberson hand-delivered the letter to the White House last week.

‘‘I was beginning to really be concerned that with literally only hours left in the president’s term, this might not happen,’’ he said. ‘‘With this one decision, President Bush has done more to improve his popularity than any single thing he could do.’’

Compean and Ramos were convicted of shooting admitted drug smuggler Osvaldo Aldrete Davila in the buttocks as he fled across the Rio Grande, away from an abandoned van load of marijuana. He remains in a low-security prison in Fort Worth, Texas.

The border agents claimed at their trials that they believed the smuggler was armed and that they shot him in self defense. The prosecutor in the case, a U.S. attorney who was appointed by Bush in 2001, said there was no evidence linking the smuggler to the van of marijuana. The prosecutor also said the border agents didn’t report the shooting and tampered with evidence by picking up several spent shell casings.

White House officials said Bush didn’t pardon the men for their crimes, but commuted their sentences because he believed they were excessive and that they had already suffered the loss of their jobs, freedom and reputations.

Compean, 32, and Ramos, 39, were sentenced to 12 years and 11 years in prison, respectively. They each have served about two years. Under the terms of Bush’s commutation, their prison sentences will expire on March 20, but their three-year terms of supervised release and the fines will remain intact.

During his presidency, Bush has granted a total of 189 pardons and 11 commutations. That’s fewer than half as many as Presidents Bill Clinton or Ronald Reagan issued during their two-term tenures. Bush technically has until noon on Tuesday when President-elect Barack Obama is sworn into office to exercise his executive pardon authority, but presidential advisers said no more were forthcoming.

In an earlier high-profile official act of forgiveness, Bush saved Vice President Dick Cheney’s former chief of staff, I. Lewis ‘‘Scooter’’ Libby, from serving prison time in the case of the 2003 leak of CIA operative Valerie Plame’s identity. Libby was convicted of perjury and obstructing justice. Bush could still grant him a full pardon, although Libby has not applied for one.

Clinton issued a total of 457 pardons or commutations in eight years in office. Bush’s father, George H. W. Bush, issued 77 in four years. Reagan issued 406 in eight years, and President Jimmy Carter issued 563 in four years. Since World War II, the largest number of pardons and commutations — 2,031 — came from President Harry Truman, who served 82 days short of eight years.