With the race for the White House heating up, the “politics of marijuana” is looming as a possibly significant factor.

Twenty-four state ballot initiatives on marijuana legalization in 16 states have been filed already and will be voted on in November 2016, including in the “swing states” of Arizona, Colorado, Florida, Michigan, Missouri, Nevada, and New Mexico.

This is important because marijuana-legalization ballot initiatives are widely acknowledged to “turn out the vote” of single-issue, first-time, and younger voters – all of whom disproportionately vote Democratic. In close races and swing states, they may make the difference. Insiders have reported that these voters have determined the outcome in several contested races and states in the last two election cycles (e.g., in Barack Obama’s defeat of Mitt Romney in Colorado in 2012).

Moreover, the marijuana-legalization issue is increasingly a focus in U.S. Senate and House races and in pro- and anti-marijuana bills. Recently, the House Republican leadership successfully stripped out pro-marijuana-legalization amendments to two pending bills.

Away from Capitol Hill, 24 states and Washington, D.C., already allow for “medical”-marijuana use – at least under some circumstances. Four states (Alaska, Colorado, Oregon, and Washington) and the District of Columbia allow adults to smoke marijuana “recreationally.”

However, proponents’ efforts to introduce marijuana into the legal and cultural mainstream have met with opposition in the workplace and the courts. Even as many states allow “medical” or “recreational” use of marijuana to some extent, the courts have upheld employers’ interests in maintaining drug-free workplaces against challenges by job applicants or employees who were not hired or have been terminated because of marijuana-related substance-abuse-prevention policy violations. Employers have prevailed in every court case brought by employees claiming a “medical”-marijuana justification for their positive drug tests after the company’s adverse employment action – including many decisions in California, Colorado, Michigan, Montana, Oregon, and Washington.

This litigation results from a clash between a culture that increasingly accepts marijuana and companies that prohibit illicit drug abuse because of legitimate safety and productivity concerns. The conflict ultimately will be resolved by Congress or the courts (four lawsuits currently are pending to invalidate Colorado’s legalization of marijuana). Meanwhile, the current Administration, through the U.S. Justice Department, has acquiesced in states legalizing marijuana, essentially by refusing to enforce the federal Controlled Substances Act in those states – an unprecedented policy. This policy could change on January 20, 2017, when a new president is inaugurated.

Thus far, most presidential contenders have shied away from the issue. However, former Texas Governor Rick Perry (R) has endorsed decriminalization. Kentucky Senator Rand Paul, a Libertarian, has consistently supported states’ rights to establish their own marijuana policies and supports decriminalizing marijuana possession. Former Secretary of State Hillary Clinton (D) has hinted that she is comfortable letting the states continue to experiment.

Conversely, New Jersey Governor Chris Christie (R) and Texas Senator Ted Cruz (R) have strongly opposed marijuana legalization, and Florida Senator Marco Rubio (R) also is on record as opposing marijuana legalization.

What the Congress does between now and mid-2016 may be critical. Supporters of marijuana legalization are gearing up. The marijuana industry has hired well-positioned lobbying firms. One of their top issues is to fix the rules that bar marijuana businesses from using banks. The well-funded National Cannabis Industry Association (NCIA) is supporting legislation that would change federal law to recognize the rights of local jurisdictions, including Washington, D.C., to create and regulate their own marijuana laws.

Finally, the U.S. Senate Appropriations Committee voted in support of opening banking services to state legal marijuana business. Senate Bill 683, the CARERS Act of 2015, introduced by New Jersey Senator Cory Booker (D), seeks to amend the federal Controlled Substances Act (21 U.S.C. § 801 et seq.) to ensure that CSA would not apply to anyone acting in compliance with state law relating to the production, possession, and distribution of medical marijuana. The proposal transfers marijuana from Schedule I to Schedule II of the CSA and prohibits federal banking officials from discouraging depository institutions from providing financial services to a marijuana-related, state-permitted legal business. A similar amendment was passed by the full House of Representatives in 2014. The House has not yet taken up the issue in 2015. House Republicans, however, supported a budget plan that would prevent legal sales of marijuana in the District until at least 2017.

Estimates indicate that the value of the legalized marijuana industry currently approaches $3 billion nationwide and is growing. Obviously, a lot is at stake.

The resolution of the marijuana-legalization issue, at both the federal and state levels, could play a significant role in determining the outcome of the upcoming presidential election.