WASHINGTON (AP) -- Lawyers for the Senate are asking a federal judge to dismiss a suit by a citizens lobbying group challenging the Senate's 60-vote threshold for overcoming filibusters.

Common Cause attorney Emmet J. Bondurant says the founding fathers never intended to allow a minority to block consideration of a bill. But the Senate's lawyer in the case -- Thomas Caballero -- said the Constitution gives the Senate the authority to make its own rules.

U.S. District Court Judge Emmet Sullivan gave no indication Monday when he would rule on the Senate's motion to dismiss the suit.

The case was heard as Senate Democratic Leader Harry Reid weighs changing the Senate rules to limit the use of filibusters. Reid complains that Republicans are using them to block Democratic President Barack Obama's agenda.