The lawmakers go on to ask if Reid would have found it constitutional if President Bush had ignored the pro formas, and if not, why it is acceptable for Obama to do so now.
"These are very serious matters," they wrote. "We hope that you share our view that neither party should undermine the constitutional authority of the Senate in order to serve a political objective."
Republicans have loudly cried foul over the president's decision to recess appoint Richard Cordray as director of the Consumer Financial Protection Bureau (CFPB), as well as three members to the National Labor Relations Board. They have contended it violates established congressional precedent, and will be subject to court challenges.
However, Democrats have maintained the move is justified, given the staunch GOP resistance to Cordray's nomination in particular. Most GOP senators vowed before Cordray was even nominated that they would block any nominee to head the new agency until several changes were made to its structure to make it more accountable to Congress.