More US Democracy

From E.J. Dionne today (h.t. Ramesh Ponnuru):

In a normal democracy, such majorities would work their will, a law would pass, and champagne corks would pop. But everyone must get it through their heads that thanks to the bizarre habits of the Senate, we are no longer a normal democracy.

Because of a front of Republican obstruction and the ludicrous idea that all legislation requires a supermajority of 60 votes, power has passed from the majority to tiny minorities, sometimes minorities of one.

Ramesh noted the inconsistency between Dionne's prior support for judicial filibusters (and though Ramesh doesn't offer a citation, I will. Washington Post Feb 20, 2003 (I can't find it online, but Dionne's column in that paper was justifying the Democrat filibuster of Estrada)) but I want to go somewhere else. We're now not a normal democracy? What changed? Lets go through some history of the Senate:

1789

At the founding the Senate is elected, not by the people, but by the State legislatures. The rules of the Senate do not allow for a filibuster

1806

Under a question by Aaron Burr, the Senate changed its rules and it became possible to refuse to cut off debate. In theory at this point a single Senator could prevent a vote on a bill

1837

The first filibuster occurs

circa 1850

In the first half of the 19th century states started conditioning their election of state representatives to their choice for the US Senate.

1913

The Constitution is changed to formally allow the citizens of a state to directly elect Senators (still not possible to force a vote on a bill if even a single Senator refuses)

1917

At the urging of Wilson, the rules of the Senate change to allow a two-thirds majority (66 votes) to overcome a filibuster.

1975

Lead by Strom Thurmond, the Senate changes the rules to the current three-fifths majority

So, now that we've had our little stroll down political memory lane, at what point in the past does Dionne think we ceased to be a normal democracy? When a Democrat made it possible to filibuster in 1806, when the progressives changed to direct election of the senate, when a Democrat changed the rules to make it a two-thirds majority to stop a filibuster, or when a Democrat changed the rules again to make it a three-fifths majority? Or was it, perhaps, when Democrats (including Dionne) decided it was acceptable to filibuster not just legislation but also nominations?