As California stares at a $24bn shortfall in its budget, it would seem no solution is too crazy to consider. The problem has inspired the newly minted assemblyman Tom Ammiano to introduce a bill that would regulate marijuana like alcohol. This measure comes as a parallel ballot initiative is being considered for 2010, and senator Jim Webb has proposed a commission to study important criminal issues in Washington.

In normal times, the idea of legalising pot would never really be taken seriously, despite impressive facts, figures and logic. However, as protesters march outside of the Ronald Reagan building in Los Angeles in response to painful budget cuts to programmes supporting disabled people, the prospect of earning the state $1.3bn in revenue per year suddenly makes the idea more palatable. While taxing marijuana consumption would not fix all budget problems and would take time to begin earning revenue, going forward it would help keep many important programmes alive during future crisis for those who need them the most.

Americans' attitudes toward legalisation may be changing, with recent polls suggesting over half now favour of the idea. However, the problem is that these polls do not ask the most important people in Sacramento or Washington: the lobbyists. Important interest groups are already downplaying the proposal as an attempt to introduce "yet another" intoxicant into society.

Moreover, federal law still prohibits even the growing of marijuana for medical purposes, let alone a comprehensive decriminalisation programme, despite calls by state legislators to harmonise federal law with states like California. While exposure to federal criminal prosecution is less likely than at the state level, and President Barack Obama has in the past indicated a willingness to change federal policy on DEA raids, it nonetheless remains a serious obstacle to legalisation efforts at the state level. But Ammiano is convinced that the Obama administration will soften its position, and that a conflict in laws could encourage a healthy dialogue by exploiting the "fuzziness" between federal and state law. This venture would at a minimum reduce criminal liability for users, and in some cases the conflict of laws may serve as a defence that juries would consider in exercising their power of jury nullification.

There can be little doubt that Ammiano will face tough resistance in Sacramento from people who see no political advantage to legalising pot or forcing a dialogue with federal authorities. However, this opposition is not insurmountable. Indeed, many conservatives support legalisation based on libertarian principles of limited government. Most people, when pressed on the issue with facts about prison overcrowding, law enforcement priorities and reducing the potency of the black market, are not as opposed to legalising pot as they might be to an issue like abortion. People are receptive to having their minds changed, if only there were some real leadership on the issue.

Treating marijuana differently from other drugs actually makes sense from more perspectives than just the bottom line. Marijuana has a lower rate of dependency than alcohol. And in record numbers, Americans are ignoring laws that keep marijuana illegal. The last time time Americans ignored a prohibition of an intoxicating substance, we created a huge black market that saw notorious figures like Al Capone emerge with the rise of organised crime. For all the good intentions of the temperance movement, it failed on many levels. Today, the revenues from black market drug sales are fuelling the Mexican drug cartels that are at war near our border. Legalisation will greatly diminish sales of the drug from cartels, since few Americans would prefer to buy illegal pot when a legal alternative is readily available.

And yet, despite the shifting financial landscape and social attitudes, some refuse to even talk about legalisation and maintain their vigil in the war on drugs. There is not a serious groundswell of support for the idea outside academic circles who are less bound by political realities such as appearing soft on crime. Interests groups are as adept at defeating ballot initiatives as they are bills in the state legislature.

But with California's finances a mess and Washington printing money at a rapid pace, the time for political games is at an end. It's easy to crack jokes and reduce the issue to cliches, but this is a bad idea that wastes money, fills prisons, forgoes revenue and fuels a black market. At a certain point, it's no longer the pot-heads who are being the most irresponsible. It's the politicians and interest groups who would rather cut programmes to disabled people than consider legalising and taxing marijuana.