Democrats will likely feel Wyden’s absence almost immediately as they try to garner enough votes to pass all of this legislation plus the START Treaty, which requires the support of two-thirds of the Senate for ratification. ~The Politico

It’s certainly true that Wyden’s absence could affect the fate of other measures before the Senate, but for the purposes of ratifying New START his absence does not change anything. The treaty will still need the same number of Republican votes to be ratified. Article II, Sec. 2 clearly states, “He [the President] shall have Power, by and with the Advice and Consent of the Senate, to make Treaties, provided two thirds of the Senators present [bold mine-DL] concur….” Wyden’s absence will bring the Democratic caucus down to 57 votes, but the number needed to ratify will also drop to 66, which still means that nine Republicans have to vote for the treaty. Ratification doesn’t get harder. It just remains as difficult as before.