Senate Democrats have used the filibuster on two-thirds of President Trump's picks to fill administration posts.

Every nominee was eventually confirmed, but the extensive use of the filibuster has slowed the process of staffing the administration to a near-crawl, leaving numerous federal agencies and departments lacking key personnel.

So far, 27 of the 41 nominees needing Senate confirmation have required Majority Leader Mitch McConnell, R-Ky., to invoke cloture, the process for ending filibusters. Cloture forces a Senate vote but also obligates the leadership to allow 30 hours of debate on the filibustered matter, effectively throwing sand in the gears of the already slow-moving legislative process. Democrats, who repeatedly denounced Republican obstructionism during the Obama administration, have shown few qualms about using the same tools now.

McConnell spokesman Don Stewart said it has been a struggle to get more than one nomination through in a week. "It has definitely slowed things down, and there has been an unprecedented level of obstruction for a president's first-term nominees. But we can get in more than one. Without cooperation, it's tough to do more than one, but we can and have," he told the Washington Examiner.

The filibusters have been held in the cases of highly controversial nominees such as Attorney General Jeff Sessions and Supreme Court Justice Neil Gorsuch but also against lower-profile figures such as Deputy Secretary of State John Sullivan, Associate Attorney General Rachel Brand and Deputy Secretary of Transportation Jefffrey Rosen.

Many of the nominees who have been filibustered do not appear to have been especially controversial, raising the question of why they were filibustered. Cloture was required to get the Senate to vote on Kristine Svinicki's nomination to be on the Nuclear Regulatory Commission. She was subsequently approved by an overwhelming 89-10 margin on June 22. Sigal Mandelker's nomination as the Treasury Department's undersecretary for terrorism and financial crimes was filibustered and then approved June 20 by a 96-4 vote.

Democrats held a different view of such tactics during the Obama administration. "We much prefer the risk of up-or-down votes in majority rule, than the risk of continued total obstruction. That is the bottom line, no matter who's in power," Senate Minority Leader Chuck Schumer, D-N.Y., said in 2013. A spokesman for the senator could not be reached for comment.

Trump has repeatedly thrown the Democrats' "obstructionist" argument against them. "Dems are taking forever to approve my people, including Ambassadors. They are nothing but OBSTRUCTIONISTS! Want approvals," Trump tweeted June 5.

Here's a list of all administration nominations voted on by the Senate. The highlighted entries required cloture votes.

June 26: Kristine Svinicki, Nuclear Regulatory Committee, filibustered

June 22: Marshall Billingslea, assistant secretary for Terrorist Financing, Treasury Department, filibustered

June 21: Sigal Mandelker, under secretary for Terrorism and Financial Crimes, Treasury Department, filibustered

June 20: Brock Long, FEMA administrator

June 12: Kenneth P. Rapuano, assistant secretary of Defense

June 8: Scott P. Brown, ambassador to New Zealand and Samoa

June 6: Courtney Elwood, CIA general counsel

May 24: John J. Sullivan, deputy secretary of state, filibustered

May 22: Terry Branstad, ambassador to China, filibustered

May 18: Rachel L. Brand, associate attorney general, filibustered

May 16: Jeffrey A. Rosen, deputy secretary of transportation, filibustered

May 11: Robert Lighthizer, U.S. trade representative, filibustered

May 9: Scott Gottlieb, commissioner of Food and Drug Administration, filibustered

May 2: Jay Clayton, Securities and Exchange Commission chief, filibustered

April 27: R. Alexander Acosta, secretary of Labor, filibustered

April 25: Rod Rosenstein, deputy attorney general, filibustered

April 24: Sonny Perdue, secretary of Agriculture

April 7: Neil Gorsuch, Supreme Court justice, filibustered

April 4: Elaine C. Duke, deputy Secretary of Homeland Security

March 23: David Friedman, ambassador to Israel Filibustered

March 21: Charles R. Breyer, U.S. Sentencing Commission

March 21: Danny Reeves, U.S. Sentencing Commission

March 15: Lt. Gen. Herbert R. McMaster Jr., national security adviser

March 15: Dan Coats, director of National Intelligence, filibustered

March 13: Seema Verma, administrator of the Centers for Medicare and Medicaid Services, filibustered

March 2: Rick Perry, secretary of energy, filibustered

March 2: Ben Carson, secretary of Housing and Urban Development, filibustered

March 1: Ryan Zinke, secretary of the Interior, filibustered

Feb. 27: Wilbur L. Ross, secretary of Commerce, filibustered

Feb. 17: Scott Pruitt, administrator of EPA, filibustered

Feb. 15: Mick Mulvaney, director of OMB, filibustered

Feb. 14: Linda McMahon, administrator of the Small Business Administration

Feb. 13: David Shulkin, secretary of Veterans Affairs

Feb. 13: Steven Mnuchin, secretary of the Treasury, filibustered

Feb. 10: Tom Price, secretary of Health and Human Services, filibustered

Feb. 7: Jeff Sessions, attorney general, filibustered

Feb. 7: Betsy DeVos, secretary of Education, filibustered

Feb.1: Rex W. Tillerson, secretary of state, filibustered

Jan. 31: Elaine L. Chao, secretary of transportation

Jan. 20: John Kelly, secretary of homeland security

Jan. 20: James N. Mattis, secretary of defense