Over the past few weeks three different senators have put the nominations of three picks by President Obama — the head of the Central Intelligence Agency, Interior Department and Labor Department — in jeopardy.

In none of these instances — CIA director John Brennan, Interior Secretary-designate Sally Jewell and Labor Secretary-designate Thomas Perez — did the senators suggest the president’s nominees were unqualified. And in the case of Jewell, Sen. Lisa Murkowski’s (R-Alaska) objection had nothing to do with the nominee herself. So the question is, why has it become so common for senators to throw up roadblocks in the confirmation process?

Interior Secretary nominee Sally Jewell.

The answer: Because Washington has become so dysfunctional, threatening a high-profile nomination has become one of the best ways senators can now achieve their normal policy objectives.

Scott Segal, head of the policy resolution group at the law firm Bracewell & Giuliani, puts it this way: “Confirmations mark one of the few times that the president can be vulnerable to congressional pressure.”

“The opportunities for senators to address important issues back home are more limited than ever," Segal added. "Targeted legislation and spending limitations are difficult to pass in a polarized Congress. So confirmation battles provide one of the few mechanisms for senators to leverage their support to focus executive branch attention on particular home-state concerns.”

Take the example of Jewell, whose nomination finally cleared the Senate Energy and Natural Resources Committee by a 19 to 3 vote on Friday. Murkowski held up her nomination in an effort to pressure the departing interior secretary, Ken Salazar, to approve a road through a wilderness area in rural Alaska. The Fish and Wildlife Service determined last month that putting a road through the Izembek National Wildlife Refuge would threaten one of the world’s most ecologically important wetlands. But Murkowski wants the road to allow the 792 residents of the remote village of King Cove easier access to an all-weather airport in the case of medical emergencies.

On Thursday, Salazar issued a memo pledging to dispatch one of his department’s top officials journey to Alaska to investigate whether the road was needed and issue a report on the matter before Interior finalizes a decision on the subject.

While it remains unclear whether Murkowski will ultimately prevail in her effort to push through a road the Interior Department has resisted for decades, environmentalists described the agreement as a dangerous concession by the Obama administration.

Defenders of Wildlife President Jamie Rappaport Clark, who headed the Fish and Wildlife Service under President Clinton, said Friday she was “troubled and dismayed that the Obama administration is playing politics with this issue.”

Sen. Rand Paul (R-Ky.) took the unusual step of waging a filibuster against Brennan to highlight his concerns about the possible use of drone strikes against U.S. citizens on American soil without a trial.

Attorney General Eric H. Holder Jr.’s response to Paul’s protest didn’t break new ground. He wrote in a letter that the administration had no intention of ever using such force but that “in an extraordinary circumstance,” such as the attacks of Sept. 11, 2001, it would be “necessary and appropriate” for the president to order military action inside the United States.

But it made Paul into a hero among conservatives, raised his national profile, and put the administration on notice that it needed to reevaluate how it conducted its drone operations.

At this moment, Perez is the one remaining second-term nominee whose confirmation is still being held hostage by the Senate. The day Obama nominated Perez, who has headed the Justice Department’s civil rights division, Sen. David Vitter said he would place a hold on it because Perez enforced Louisiana’s voting rights laws in a way “that specifically benefits the politics of the president and his administration at the expense of identity security” of the state’s registered voters. Vitter noted he is still awaiting a reply from the Justice Department in connection to a letter he wrote on the subject in 2011, and would not release his hold until he received an answer.

It remains unclear how serious a problem this will be for Perez, who has also come under attack from other GOP senators. But Segal — who often makes common cause with Republicans in his efforts to defend coal-fired power plants — said there are limits to using the confirmation process to extract concessions from the White House.

“Of course,” he noted, “senators must keep their objectives reasonable and at least somewhat germane to the appointment subject to confirmation or they risk losing credibility.”