Senate Majority Leader Harry ReidHarry ReidChris Murphy’s profile rises with gun tragedies Republicans are headed for a disappointing end to their year in power Obama's HHS secretary could testify in Menendez trial MORE (D-Nev.) also announced Tuesday night that his chamber would vote on a motion to proceed on the 21st Century Postal Service Act (S. 1789) on Thursday. On Tuesday, Reid said he would "fill the tree," or stack the process with his own amendments to prevent others from being considered, on the legislation after Sen. Rand PaulRandal (Rand) Howard PaulHouse bill set to reignite debate on warrantless surveillance Authorizing military force is necessary, but insufficient GOP feuds with outside group over analysis of tax framework MORE (R-Ky.) announced his intention to attach an amendment cutting U.S. funding to Egypt.

Sen. Joe Lieberman (I-Conn.), one of the cosponsors of the bill, also signaled on Tuesday that he hoped to find some kind of compromise between Republicans and Democrats over possible additional amendments.