With Sanders and Lieberman the Democrats have 51 votes which are just enough to elect the majority leader (a fifty-fifty split would have the Vice President cast the tie vote and let the GOP be in control).Don't fool yourself. They may not have 50 "Democrat" members, but they have Bernie Sanders from Vermont , a "Democratic Socialist" and Joe Lieberman from CT.
You can' t get anymore left leaning than Sanders and Joe is still sympathetic to many Democratic party ideals. So why no change? Or could it be they all sleep in the same bed?
That does not change the fact that, as I wrote in my earlier post, it takes 60 votes to get anything accomplished in the Senate.