President Barack Obama's only second term Hispanic cabinet member nominee, Thomas Perez, was poised to be approved by the Senate Thursday to head the Labor Department.

Lawmakers, by the thinnest of margins, voted to remove obstacles blocking the confirmation while honoring a bipartisan pact for approving top nominations.

Senators were ready to confirm Perez as labor secretary by a likely near party-line roll call. After that, they were scheduled to debate Obama's selection of Gina McCarthy to become administrator of the Environmental Protection Agency.

Perez, who leads the Justice Department's civil rights division, is considered too liberal by many Republicans. On Wednesday, GOP senators said they were opposing him because he has refused to obey a House subpoena demanding his personal emails related to a whistle-blower case against the city of St. Paul, Minn., that they have criticized him for dropping.

On Wednesday, the Senate voted narrowly to end a filibuster against Perez. All but six Republicans voted against Perez — the exact number of GOP senators that majority Democrats needed to muster the 60 votes required to end the delaying tactics against Perez's nomination.

The fight against the decision to end debate on Perez’s nomination in the Senate was led by Senator Marco Rubio (R-Fla.), who specifically called out six fellow Republicans who voted for ending the Senate's debate.

“Members, you are about to vote to give 60 votes and cut off debate on a nominee that has ignored a congressional subpoena from the House on information relevant to his background and to his qualifications for this office,” Rubio said from the Senate floor.

In his first term, Obama had two Latino cabinet members — Hilda Solis as Labor Secretary and Ken Salazar in charge of the Interior Department. National Latino leaders had expected Obama to keep at least two for his second term, but so far there have been none - until now. Latino organizations had demanded at least three Hispanic members of the White House cabinet, which includes 22 positions overseeing departments, days after Obama's second term nomination in recognition of the political power of the Hispanic community displayed in the 2012 presidential election.

The National Hispanic Leadership Agenda, an umbrella group incorporating the nation’s largest Latino rights group, has led the effort for Perez’s appointment. With the confirmation hearing scheduled for next week, NHLA is making a final push.

“Tom Perez is on the verge of making history as the first Dominican American Cabinet-level appointee in the nation,” the organization told supporters in an email sent on Thursday.

That 60-40 vote was the closest senators have come to unwinding this week's deal between the two parties that has averted all-out partisan warfare in the chamber over nominations and Senate rules. That roll call seemed to signal that while GOP leaders would deliver the votes needed to honor the bipartisan agreement, numerous Republicans were rankled by the pact and unhappy with Perez.

In exchange for the GOP halting filibusters against seven of Obama's top nominees, majority Democrats dropped a threat of a rules change that would have prevented opponents from requiring a 60-vote threshold to end filibusters of top agency appointees. That ability to wage filibusters unless the hard-to-achieve 60 votes are accumulated has long been prized and utilized by minority parties.

The other five nominees involved in the deal are Richard Cordray, whom the Senate confirmed Tuesday as director of the Consumer Financial Protection Bureau; Fred Hochberg, whom the Senate approved Wednesday to continue leading the Export-Import Bank; labor lawyers Nancy Schiffer and Kent Hirozawa to join the National Labor Relations Board; and NLRB Chairman Mark Pearce, whom Obama wants to keep in the role.

McCarthy, who currently heads the EPA's air pollution office, has helped craft rules aimed at reducing pollutants from power plants and other sources. Republicans have long criticized the agency for championing overly restrictive regulations that they say kill jobs.

Last week, Louisiana Sen. David Vitter, top Republican on the Senate environment committee, said he was dropping efforts to delay McCarthy's nomination after the EPA agreed to release more information about how it makes decisions. McCarthy has also faced opposition from Sen. Roy Blunt, R-Mo., because of delays to a flood control project.

Based on reporting by the Associated Press.

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