Republican opponents of a nuclear arms reduction treaty with Russia can do little to stop what appears to be a growing momentum to ratify the agreement in coming days.

With one senator, Ron Wyden, D-Ore., out of commission due to cancer surgery, 66 lawmakers, rather than the usual 67, are needed to ratify the treaty under the required two-thirds rule for passage, and it appears there is now enough support among GOP Senators to reach that threshold.