|From The Hill|
Why 60? While it's true that a simple majority can pass bills, under the rules of the Senate a filibuster can be used to delay the vote. So as long as any senator wishes to speak on a bill, that bill cannot be put to a vote - unless a motion (called a cloture) is made to vote on the bill by at least 60 senators.
As long as Republicans filibuster a bill and deny the cloture, any bill Obama and the Democrats could be delayed indefinitely. And while that sounds impossible, it seems from day one Republicans were determined to block any bill Obama supported. There's a number of bills that have failed due to this strategy (and that list isn't up to date).
That's why the fact that while Democrats had the majority in the Senate, they couldn't pass the bills they wanted because they didn't have the 60 members they needed. And before you ask, Obamacare passed by a near miracle. And Republicans threw a fit.
The point of all this is not to dismiss Sanders as a lost cause but to learn what needs to happen in the future. If we support Sanders as president, then we need to support a Democratic congress. We need to make sure we have not only the exact number of Democrats in the House and Senate needed to pass bills, we need as many Democrats as possible. We have to make sure the bills Sanders wants to pass can be passed. And we can only do that by going out to the polls and voting.
If Sanders is elected President and we have a split or Republican-ruled Congress, the fight to change this country is going to be just as impossible as with Obama.