IT’S NOT SUPPOSED TO BE THIS WAY…. There’s a common misunderstanding in politics, especially among political reporters, that the Senate has always required a 60-vote supermajority to pass every meaningful piece of legislation. That’s nonsense.

As Matt Yglesias recently noted, “Simple logic indicates that this is false — it used to require a unanimous vote to end a filibuster and, obviously, non-unanimous bills passed. But there are more examples. For example, before the 1970s you needed two-thirds of the Senate to end a filibuster, but the Lend-Lease Act went through the Senate on a 60-31 vote (according to the rules of the day, you would have needed 66 as there were only 98 Senators) without the minority obstructing the bill…. [R]outine filibustering is a new tradition and not a time-honored principle of American government.”

And yet, it’s treated as if it were a historical norm, instead of a bizarre fluke with no foundation in the American legislative or political tradition. We’re supposed to have a process in which legislation becomes law after passing both chambers of Congress and receiving the president’s signature. Now, however, after no discussion or formal debate, we somehow got stuck with a system in which 41 senators can block a vote on almost anything they choose.

It is, as this chart from Norm Ornstein makes clear, an entirely modern creation.

If you’re having trouble making out the years, note that as recently as the 1960s, filibusters were rare (and as it turns out, largely inconsequential). Now, they’re an assumed hurdle for practically every bill. The last Congress broke a record, and there’s every reason to believe Republicans’ obstructionist tactics will break the record again in the 111th Congress that ends next year.

This distorts the legislative process to an unrecognizable degree. There is no justification for this. None.

As Ezra Klein explained, “If you want to understand why the earth is likely to heat and why comprehensive health reform is unlikely to pass and why the government is increasingly letting the Federal Reserve govern its response to the financial crisis, that graph basically tells the story.”

Elected leaders have to do better than this. The American electorate can give a party the White House and sizable majorities in both chambers, but that party will still struggle badly to pass its agenda, due entirely to a distortion of institutional constraints. A 41-member minority party can block legislation — controversial or not — by abusing an obscure procedural tactic that was never intended to be used to necessitate supermajorities on literally every piece of legislation.

What was once an exceedingly rare challenge, used under extraordinary circumstances, has become — after no public discussion at all — a mandatory supermajority simply to govern. Without reform, necessary legislation on life-or-death policies may enjoy the support of the House majority, the Senate majority, the president, and most Americans, and still may not pass because a small Senate minority says so.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.