The decision to try to compel cooperation from a leading judicial activist and a Republican megadonor came over fierce G.O.P. opposition and threats of retaliation.

All 11 Democrats on the Senate Judiciary Committee voted to approve subpoenas for Harlan Crow and Leonard Leo.

WASHINGTON (Reuters) - Senate Democrats are expected on Thursday to vote on authorizing subpoenas to a pair of influential conservatives with ties to the U.S. Supreme Court as part of an ethics inquiry spurred by reports of undisclosed largesse directed to some conservative justices.

Democrats issued the subpoenas over heavy objections from Republicans, who called the subpoenas "an absolute joke."

All 11 Democrats on the Senate Judiciary Committee voted to approve subpoenas for Harlan Crow and Leonard Leo.

A Democratic-led U.S. Senate panel on Thursday authorized subpoenas to two influential conservatives - Harlan Crow and Leonard Leo - as part of an ethics inquiry spurred by reports of undisclosed largesse directed to some conservative Supreme Court justices.

In a rush of rule-breaking at the end of a meeting, Mr. Durbin moved to bluster through subpoenas for two friends of Supreme Court Justices on a partisan vote. This is part of a Democratic political campaign to portray the High Court as a trinket bought by billionaires.

The Supreme Court has confronted several tough-to-defend ethics controversies this year, which has now led to new Senate Judiciary Committee subpoenas.