Senate Republicans blocked a batch of mostly minor nominations by President Barack Obama late Monday in the aftermath of last month’s Democratic move weakening the minority party’s traditional ability to block most presidential appointments.

The action demonstrated that the GOP was intent on exacting a price for the changes majority Democrats muscled through the Senate in filibusters, or procedural delays minority senators can use to delay or kill nominations or bills.

Monday’s confrontation came as the Senate returned to work for the first time since Democrats made those changes on Nov. 21.

That Democratic moved had angered Republicans, both because it weakened the GOP’s ability to wage filibusters and because Democrats made the change with a simple majority of votes. Republicans said Democrats should have been required to win a two-thirds majority to make the change, which is more commonly used to make major rules changes.

On Monday, Sen. Lamar Alexander, R-Tenn., objected to a request by Senate Majority Leader Harry Reid, D-Nev., for unanimous approval of more than 30 mostly minor appointees.

“Until I understand better how a United States senator is supposed to operate in a Senate without rules, I object,” Alexander said.

The nominees blocked included posts like an undersecretary of defense for personnel and readiness and a pick for the Chemical Safety and Hazard Investigation Board. Also included was Deborah Lee James, Obama’s choice to be secretary of the Air Force.

The quick approval for those nominees that Reid was seeking required the consent of all senators, so Alexander’s objection was enough to stop them.

The dispute came to a head last month after Republican blocked Obama picks for three vacancies for the U.S. Court of Appeals for the District of Columbia Circuit. Those nominees were not included in the group blocked Monday.

That court is extremely powerful because it rules on administration actions. Its eight judges are currently divided evenly between those picked by past Democratic and GOP presidents.

When Alexander likened GOP objections to Democratic actions against judges chosen by GOP President George W. Bush, Reid said, “That explanation is as flat as a bottle of beer open for six months.”

The changes Democrats made allow filibusters to be ended by a simple majority of senators, not the 60 votes required since 1975. The changes apply to nearly all nominations, but do not affect nominated Supreme Court justices or legislation.

Reid also set in motion votes to end filibusters against Jeh Johnson, his pick to lead the Department of Homeland Security, and nine minor nominees.

(AP)