Washington (CNN) -- Attorney General Eric Holder sought to defend his department's budget request Tuesday in a House subcommittee hearing that veered directly into several hot-button issues, including the Obama administration's recent decision to no longer defend a key portion of a federal law barring recognition of gay marriage.
Rep. Frank Wolf, R-Virginia, chairman of the House Appropriations Subcommittee on Commerce, Justice and Science, said "Congress has a reason to be concerned" about that decision and that the Department of Justice "has a duty to defend the constitutionality of the laws of the United States, and has a long history of doing so."
Wolf cited as an example former Solicitor General Ted Olson's defense of a campaign finance reform law that the conservative Republican, personally, "surely would have rejected."
Holder said "the legal landscape has changed" in the 15 years since the Defense of Marriage Act became law, and that several lower courts have declared it unconstitutional.
He referred to two prior instances in which the department did make arguments in support of the DOMA, using a "more permissive standard." However, he said, by "applying a higher scrutiny standard" that took into consideration "the history of discrimination that gays and lesbians have endured in our nation's history ... we made the determination that the statute could not pass constitutional muster, and the president instructed me not to defend the statute on that basis."
Wolf promptly characterized that as the administration's "decision to abandon your duty to defend this law." He questioned whether it could be "viewed as a case of political opportunism," given the department's consistent defense of the law since it was passed by Congress and signed into law in 1996 by President Bill Clinton.
"I can tell you that what we did was apply the facts of the law in a neutral and detached way, and made the determination that the announcement I made was an appropriate one," Holder replied. "It was not a decision that I took lightly; we take very seriously our responsibility to defend statutes that Congress has passed."
Republicans found fault with the Obama Justice Department on other issues, including its handling of a voter intimidation claim, drug enforcement issues and the status of the detention center at Guantanamo Bay, Cuba.
Rep. John Culberson, R-Texas, said the department has not cooperated fully with the U.S. Civil Rights Commission's investigation of alleged voter intimidation by two members of the New Black Panther Party at a Philadelphia polling place in 2008.
Culberson said the commission's report indicates Justice Department lawyers were encouraged to be aggressive in defending blacks from voter intimidation and other forms of harassment but were discouraged from being as active fighting discrimination against whites.
The congressman referenced a quote from a former Democratic activist who said the Philadelphia incident was the most serious act of voter intimidation he had witnessed in his career.
Holder said that implication "just flies in the face of history."
He denied the Justice Department makes decisions based on race and said he took the issue particularly personally because his sister-in-law, the late Vivian Malone Jones, helped integrate the University of Alabama. Holder said the New Black Panthers case is not a good comparison "to what happened to my people" and that it is a disservice to those who risked their lives during the civil rights battles of the '60s.
When Kentucky Republican Harold Rogers got his turn to question Holder, he angrily complained about the prescription drug abuse problem in his state and said the Justice Department should be doing more to shut down operations in Florida that supply many of the pills illegally.
Holder insisted he was committed to finding solutions to the drug problem and had plenty of experience seeing how drugs affected people's lives during his time as a judge.
The attorney general was asked about the administration's efforts to close Guantanamo, which holds 172 prisoners, including self-proclaimed 9/11 mastermind Khalid Sheik Mohammed. Wolf asked whether the administration will be able to close Guantanamo before the end of President Obama's first term in office. Holder replied, "I don't know."
According to Holder, the administration is still determined to close Guantanamo, which it views as a potent recruitment symbol for al Qaeda. But Holder noted Congress has blocked funding for bringing the detainees to the United States to be imprisoned and in some cases to face trials in civilian courts.
Obama's fiscal year 2012 budget request for the Justice Department totals $28.2 billion, which represents a 1.7% increase in budget authority and 2,095 more positions than the continuing resolution for fiscal year 2011, according to a department statement.
CNN's Carol Cratty and Cameron Tankersley contributed to this report.