04/18/2013 03:20 pm ET Updated Jun 18, 2013

Why 90 Percent Isn't Enough: The Real Reason Gun Control Failed

In my past life as a political science professor, I was occasionally stumped by a question about American politics that I could not answer. At first glance, 46 senators voting against a measure with 90 percent public approval seems like such a question. But it's actually fairly easy to explain, and it doesn't have as much to do with the NRA's money as people think. It has a great deal to with the small state bias that has made the US Senate one of the least democratic legislatures in the world.

Think about that for just a minute. The US senate is one of the least democratic legislatures in the world. According to the think tank National Democratic Network, "[F]ifty percent of the U.S. population is concentrated in only nine states." This means "the other fifty percent of the population is awarded 82 Senators."

The list of 46 senators who voted against Manchin-Toomey is chock full of low-population states, such as Nebraska (1.8 million at the 2010 census) and Wyoming (576,412). So a national poll that's weighted to get a national sample barely touches their constituents. They could be punished for following the national will at their next election.

The Democratic senators who voted against the Manchin-Toomey background check bill come for the following states: Alaska, 47th in population at around 730,000; North Dakota, 48th in population at nearly 700,000; Arkansas, 32nd in population at almost 3 million; and Montana, 44th in population at just a bit over 1 million. Believe me, these Democratic senators are not just voting that way because of NRA money.

In these low-population states, a senator may have nothing at all to fear from voting against a measure favored by 90 percent of the American people, as long as that vote is consistent with a minority of a minority within each state. That's the base in a primary election. A senator looking for reelection first needs a majority of her or his own party's voters in a primary, and primary elections are traditionally low turn-out affairs. Only the most active voters (usually the angriest) turn out in a primary.

So it's not as simple as getting somebody to run against these folks in a primary or a general election. No matter how much money the folks who support sensible gun control (and I am one of them) spend in these elections, it is extremely hard to change the electorate in a low-population state's primary.

If we aren't going to change our Constitution to fix this imbalance, then the very least that needs to be done is the elimination of the 60 votes needed to end a filibuster. In fact, given this imbalance, it's time to end the filibuster entirely, whether they talk like Rand Paul or just quietly round up the votes to prevent the other side from getting to the magic 60.

Ending the filibuster should be a national rallying cry. No issue with 90 percent national support should be able to be defeated in the U.S. Senate. And then, we need to do something about the gerrymandered House districts that allow one party to get a million more votes for congressional candidates, and remain a minority in the House chamber. That is, we need to do these things if we want to continue to call ourselves a working democracy.