Recent mass shootings have prompted one Missouri lawmaker to propose an additional tax on "violent" games, despite those tragedies lacking a proven link to games, the failure of similar measures in other states, and the likely unconstitutionality of such a tax.

Republican State Representative Diane Franklin of rural Camdenton has introduced House Bill 157 (PDF) that would add a one percent excise tax on the sale of games rated T or above by the ESRB. That wide umbrella would include violence-free games like Guitar Hero and Ultimate Card Games that received a T rating for "suggestive lyrics" and "simulated gambling," respectively. But hey, at least Call of Duty would set someone back an additional 60¢ under the plan.

Money raised by the proposed tax would go toward "the treatment of mental health conditions associated with exposure to violent video games," according to the language of the bill. That's a bit odd, because while there is conflicting evidence on whether video games can lead to an increase in loosely defined "aggression" or violent feelings, we're not aware of any studies that link exposure to violent video games to the development of mental health conditions. Never mind that, though; "history shows there is a mental health component to these shootings," Franklin said, according to the AP.

It was about this time last year that a similar excise tax was proposed by an Oklahoma lawmaker, only to fail in committee. Other taxes focused on violent games have been proposed in Wisconsin and New Mexico in recent years, though neither came close to passage. Last month, US Senator Jay Rockefeller (D-WV) proposed funding additional studies into the effects of violent games on behavior, but the plan failed to advance.

Even if this Missouri bill were to somehow buck the trend and be signed into law, there's some question about whether or not such selective taxation would be altogether legal. The Supreme Court established full First Amendment protection for video games in 2011, and there's significant case law (PDF) suggesting that the government can't single out a specific type of speech for taxation absent a "compelling state interest."

All in all, we should be less worried about the actual threat posed by these kind of proposed taxes and more concerned with the fact that bills aimed at violent video games continue to be a favorite cudgel for some legislators to try to score cheap political points.