Adam Liptak at The New York Times has put together a long, fascinating article on the disproportionate influence enjoyed in the Senate by the least populous states, which has grown so much in recent years that the upper chamber has become one of the least democratic institutions in the developed world.

Small states like Vermont and Wyoming not only receive much more federal money (as measured in dollars per person), but can wield immense power to stymie largely liberal reforms on a host of issues — including gun control, immigration, and campaign finance — that often have the support of senators who represent a clear majority of the country. According to Liptak:

To be sure, some scholars and members of Congress view the small-state advantage as a vital part of the constitutional structure and say the growth of that advantage is no cause for worry. Others say it is an authentic but insoluble problem.

What is certain is that the power of the smaller states is large and growing. Political scientists call it a striking exception to the democratic principle of "one person, one vote." Indeed, they say, the Senate may be the least democratic legislative chamber in any developed nation.

Behind the growth of the advantage is an increase in population gap between large and small states, with large states adding many more people than small ones in the last half-century. There is a widening demographic split, too, with the larger states becoming more urban and liberal, and the smaller ones remaining rural and conservative, which lends a new significance to the disparity in their political power. [The New York Times]

According to one metric, the voting power of a senator from Wyoming is 66 times greater than a senator from California — one of the highest such disparities in the developed world, outdone only by legislatures in Argentina, Brazil, and Russia. To think about it another way, California's 38 million residents have only two senators, compared with 44 senators for the 38 million people living in the 22 smallest states.

As Liptak notes, small states are supposed to have a disproportionate amount of power. The Great Compromise of 1787, which paved the way for the creation of the United States, was designed to protect smaller states from the tyranny of the majority. But the problem has grown to such an extent that some liberal groups are calling for change. 

It won't be easy. The Senate's structure is baked into the Constitution, which would require a constitutional convention to change.

Another possibility is reforming the filibuster, which has given senators from small states even more power. "While the Framers hoped for a slow-moving Senate, they didn't design it with a supermajority requirement in mind," says Jamelle Bouie at The American Prospect. "The filibuster is an extra-constitutional innovation. Moreover, there's a difference between holding legislation (or nominees) for further debate, and using the difficulty of attaining a supermajority to kill legislation outright, even it has ample support from majorities in both chambers of Congress."