WASHINGTON - Democrats used their newly initiated lower threshold for defeating filibusters Monday to win Senate confirmation of President Obama's nomination of former top Pentagon lawyer Jeh C. Johnson to be secretary of homeland security.

On a 57-37 vote, Democrats broke a GOP blockade against Johnson before the Senate minutes later confirmed him on a 78-16 vote. Until Democrats unilaterally changed the Senate's filibuster threshold on presidential nominations, it would have taken 60 votes to clear Johnson for a final vote.

Anne W. Patterson, currently the U.S. ambassador to Egypt and formerly ambassador to Pakistan, also won confirmation Monday to become assistant secretary of state in charge of Near Eastern affairs. She also was confirmed 78-16, with all of the "no" votes coming from Republicans. A career diplomat, Patterson entered the State Department's foreign service in 1973.

Johnson is replacing Janet Napolitano as head of the Homeland Security Department. About 40 percent of the senior leadership positions are now vacant, and Johnson said that filling those posts was among his top priorities.

In a statement, Obama praised the Senate for confirming Johnson, calling him "a critical member of my national security team."

"And he helped to shape some of our most successful national security policies and strategies," the president added.

Obama has in the past praised Johnson's role in overturning the ban on openly gay service members in the military.

Sen. Jeff Sessions (R., Ala.) questioned Johnson's experience for heading homeland security, a department created after the 9/11 attacks from more than two dozen disparate agencies and now perhaps the most complex in Obama's cabinet.

"I'm not saying he's not a good man, but he's not a good choice for this," Sessions said.

On Friday, Sen. John McCain (R., Ariz.) said he was also troubled because Johnson did not answer all of his questions about immigration policy during his confirmation process.