In a conference call with reporters this afternoon, Department of Homeland Security secretary Janet Napolitano argued that passing the DREAM Act would help authorities enforce current immigration laws.

“The DREAM act will enable DHS to prioritize to an even greater extent enforcement of our nation’s immigration laws,” said Napolitano, adding that it does not make “much sense” to use the department’s resources “to prosecute young people … [who] want to go to college or serve in the armed forces.”

Mentioning that the DREAM Act would require background checks of all applicants, Napolitano said, “No one who poses a threat to public safety will be able to adjust their immigration status.” She did not explicitly address concerns that the DREAM Act would allow young adults with some misdemeanors, including having a DUI, to remain eligible for receiving legal status.

That’s a concern emphasized by Sen. Jeff Sessions (R., Al.), who wrote a letter to his fellow senators today asking them to oppose the DREAM Act. “The DREAM Act is poorly drafted, filled with loopholes and, by rewarding illegal behavior, will without doubt encourage future illegal immigration,” he wrote. “This irresponsible proposal would almost immediately legalize an estimated 1.3 – 2.1 million illegal aliens — a number expected to grow as the bill has no cap or sunset. At the same time, the bill would provide safe harbor, and even amnesty, for aliens who have committed serious crimes.”

Sessions also argued that that none of the four versions of the DREAM Act currently under consideration had been vetted properly, since they had not been “reviewed by the Judiciary Committee” or scored by the Congressional Budget Office.

He also expressed concerns about how passing the act would impact U.S. immigration policy. “This bill would create an incentive for future illegality since Congress would be sending a message that we have effectively given up on enforcement of our immigration laws and instead seek to reward those who illegally enter the country,” Sessions warned. “At a time when our immigration system is in disarray, this legislation will allow millions to flood the courts and undermine the small progress we have made toward lawfulness.”

The laws themselves need to be … updated and reformed,” argued Napolitano. “While it is not a substitutive for CIR [Comprehensive Immigration Reform] … it’s [DREAM Act] good for the nation. It’s good for immigration enforcement because it allows us to further target our efforts,” she said, calling young adults the “least culpable” group.

When New York Times reporter Julia Preston asked Napolitano if the administration had received any Republican support on immigration matters in exchange for the administration’s decision to pursue enforcement of immigration laws (which Preston appeared to view as a Republican-leaning position), Napolitano said she didn’t view law enforcement as a “quid pro [quo].”

“We enforce the law because we took an oath to enforce the law,” she said.

Sessions maintained the need to stem illegal immigration first. “We have failed to secure the border, and passage of this legislation would signal to the world that we are not serious about doing so,” he wrote. “Now is not the time to proceed to this controversial measure.”