The abrupt departure of Homeland Security Secretary Janet Napolitano Friday garnered mix reaction from lawmakers, particularly within the Republican Party.

Not one to mince words, Sen. Jeff Sessions, R-Ala., who clashed with Napolitano on the Senate Judiciary Committee, said the exiting cabinet member's tenure was "defined by a consistent disrespect for the rule of law."

"The most significant obstacle to immigration reform remains President Obama's selective enforcement of the law," added Sessions, a "nay" vote earlier this month on the immigration reform bill. "Any selection  interim or permanent  to replace Secretary Napolitano must disavow these aggressive non-enforcement directives or there is very little hope for successful immigration reform."

Other Republicans were much more measured in their assessment of Napolitano's time at the head of Homeland Security, which lasted all of Obama's first term. Sen. John McCain, a Republican who, like Napolitano, hails from Arizona, said he was "proud of our former governor's service."

"Janet Napolitano has served our nation with honor over the last four years as Secretary of the Department of Homeland Security  one of the toughest and most thankless jobs in Washington," said McCain. "We have had our share of disagreements during her time as secretary, but I have never doubted her integrity, work ethic or commitment to our nation's security."

Napolitano, who is leaving to head California's university system, departs just as immigration reform shifts to the House, which is decidedly more averse than the Senate to finding a compromise to the decades old problem. Her successor has not been named, but few of Obama's recent appointees have enjoyed an easy path to confirmation and his next pick for Homeland Security will receive increased scrutiny from Republicans amid the immigration debate.

House Minority Leader Nancy Pelosi, D-Calif., lauded Napolitano's service and celebrated that the former secretary will take over the university system in Pelosi's home state.

"The students of the University of California schools will benefit each and every day from Secretary Napolitano's sharp mind and strong leadership," Pelosi said. "As the first woman to lead the UC system, Secretary Napolitano will offer a unique voice to this critical position."

Only five of Obama's original cabinet members, those who have been with him since he took office in 2009, remain by his side  Attorney General Eric Holder, Secretary of Health and Human Services Kathleen Sebelius, Secretary of Education Arne Duncan, Secretary of Housing and Urban Development Shaun Donovan and Secretary of Veterans Affairs Eric Shinseki.