Brian Schaffner sends this graph and commentary:

The Senate voted down new restrictions on gun ownership on Wednesday, drawing the ire of President Obama and a number of other politicians and pundits who, among other things, pointed to the Senate’s actions as contrary to public opinion on the issue. But to what extent did senators really vote in opposition to their constituents on this issue?

The 2012 Cooperative Congressional Election Study asked respondents whether they felt that “the laws covering the sale of firearms should be made more strict, less strict, or kept as they are?” 54,451 respondents provided an answer to this question, allowing more than sufficient numbers to generate meaningful samples in each state. This chart shows the proportion of respondents in each state who said that gun laws should be made more strict. The color of each state indicates the number of senators from that state who voted in favor of the assault weapons ban on Wednesday. Blue states were those where two senators voted in favor of the ban, red states are those where two senators voted against, and purple states saw their senators split on the vote.

Note that in every state where a majority favored stricter gun laws at least one of the two senators voted in favor of the assault weapons ban. On the other hand, only 17 of the 74 senators representing states where fewer than 50% of citizens wanted stricter regulations voted in favor of the ban. Also challenging for gun control advocates is the fact that while only 13 of the 50 states had 50% or higher support for stricter gun laws, many of these are the most populous states. In fact, about 45% of the U.S. population lives in these 13 states, yet those states account for only 26% of the Senate’s membership. The populations of California, Illinois, New Jersey, Pennsylvania, Florida and New York are some of the strongest supporters of stricter gun laws, but their voice in the Senate is the same as much smaller states whose populations comprise some of the biggest opponents, such as South Dakota, Alaska, Montana, West Virginia, Wyoming, and Utah.