American voters heading to the polls for the midterm elections will be deciding on more than just their pick of lawmakers at the ballot box on Tuesday.

In addition to choosing senators and state governors – and therein determining whether the Republicans or Democrats hold a controlling majority in the Senate and House of Representatives – the electorate are also voting on crucial matters of policy at a state level.

In Idaho, Utah and Nebraska, for instance, voters will decide whether to extend Medicaid. In West Virginia, Oregon and Alabama, access to abortion will be under the microscope.

The legalisation of marijuana is also up for debate, one of the most divisive topics in the current American political landscape.

Despite cannabis being the subject of a federal prohibition, nine states and the District of Columbia all now permit its recreational use while 30 allow its administering on medical grounds.

On Tuesday, North Dakota and Michigan will decide whether to permit recreational use while Missouri and Utah will ask voters whether the drug should play a role in healthcare.

In North Dakota, Measure 3 sets a minimum purchase age of 21, erases pot convictions from criminal records and adds new penalties for those found selling it to minors.

In Michigan, Proposal 1 sets an age limit of 21, compels the state to establish a licensing system for growers and sellers, allows local businesses to prohibit its consumption on their premises and places a 10 per cent sales tax on cannabis.

In Missouri, the new proposal would change the state's constitution to make it harder to change marijuana laws in future and similarly prompt the state to build a regulatory system.

In Utah, Proposition 2 will make it legal for sufferers to access pot but not in a smokable or edible form or to grow their own supply at home.

The increasing liberalisation of attitudes towards marijuana, typically in left-leaning states, is grounded in research suggesting it can be used to soothe a range of ailments and complaints, from chronic muscle pain or nausea during cancer treatment to relieving the symptoms of glaucoma, Crohn’s disease, Parkinson’s, multiple sclerosis and childhood epilepsy.

US midterm elections: the voters Show all 10 1 /10 US midterm elections: the voters US midterm elections: the voters Ross Kershey of Exton, Pennsylvania objects to President Trump's recent threat to unilaterally suspend the constitutional protection of birthright citizenship as a way to control undocumented immigrants AP US midterm elections: the voters Thomas Jakel of Eveleth Minnesota is a former miner. The economy is the most important thing to voters in his town AFP/Getty US midterm elections: the voters Jerry Mcneff of Exton, Pennsylvania intends to split his ballot between the parties for Pennsylvania's House, Senate and governor elections AP US midterm elections: the voters Jean Hoffman of Exton, Pennsylvania has concerns about the cost of her daughters' college education. She thinks that voting Republican might help extend the economy's rise AP US midterm elections: the voters Supporters attend a rally of President Trump in Rochester, Minnesota AFP/Getty US midterm elections: the voters Supporters attend a rally of President Trump in Rochester, Minnesota Reuters US midterm elections: the voters Supporter Jenny Haley and son wait in line to see a Trump Rally in Rochester, Minnesota AFP/Getty US midterm elections: the voters Dick Calef of Exton, Pennsylvania is a life-long Republican. He credits the economic gains in suburban Philadelphia to longer-term factors beyond Trump's policies, such as the growth of internet and health care companies. He's not yet sure how he will vote AP US midterm elections: the voters Markus Fasel of Mendota Heights, Minnesota attends a campaign event for Democrat Angie Craig, his favoured congressional candidate AFP/Getty US midterm elections: the voters Supporters attend a rally of President Trump in Rochester, Minnesota Reuters

Democrat Beto O’Rourke, running against Ted Cruz for the Texas Senate, is one of the most high-profile liberal candidates to have called for decriminalisation during the current campaign season.

An unofficial lobbying day known as “420” – started by a group of Grateful Dead fans in California in the 1970s – takes place on 20 April every year to call for the wider acceptance of weed.

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Arkansas, California, Florida, Massachusetts, Nevada and North Dakota all increased access to marijuana in 2016, a watershed year for the issue.