As the presidential election approaches, Democrats and advocates for low-wage workers are readying a major push to advance a key policy goal: raising the minimum wage.

Voters in Arizona, Colorado, Maine, and Washington will decide whether to increase their states’ minimum wages. Meanwhile, a labor-backed group that has been a leader on the issue is set to inject it into a slew of competitive Senate races — to the benefit of Democratic candidates. By luring young voters and minorities to the polls, the issue could even offer Democratic presidential nominee Hilary Clinton a crucial boost in a close general election.

“This is going to be a driver for Democratic base voters, especially for low-income voters and communities of color,” said Patty Kupfer of Colorado Families for a Fair Wage, which is helping to coordinate the effort there.

“This is going to be a driver for Democratic base voters, especially for low-income voters and communities of color."

In the last few years, as concerns have grown about economic inequality, proposals for a higher minimum wage have enjoyed remarkable success, thanks in part to an energetic campaign for a $15 minimum wage led by fast-food workers and backed by organized labor. New York, California, and Washington D.C. have all passed laws to raise their minimum to $15 an hour within the next eight years.

This fall's ballot initiatives wouldn’t go that far. The Arizona, Colorado, and Maine measures would set a wage of $12 an hour by 2020, up from $8.05, $8.31, and $7.50 respectively. The Washington measure would raise it to $13.50 by 2020, up from $9.47. The Arizona and Washington initiatives also would require paid sick leave.

Ryan Johnson, the executive director of the Fairness Project, which has been the driving force behind the ballot initiatives, said his group decided to act after lawmakers in several states rejected proposals for a raise despite strong public support.

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Related: Democrats Add $15 Minimum Wage to Platform

“Legislatures are not responding to what people clearly do want and need in order to be able to live and prosper in this economy,” Johnson said.

Supporters also hope the initiatives’ mere presence on the ballot will spur lawmakers to address the issue. California Gov. Jerry Brown and Washington D.C. Mayor Muriel Bowser both have said that ballot measures to raise the wage prompted them to act.

"I guess what really cemented this deal was ... quite frankly the specter of the initiative," Brown said this year after forging an agreement with legislative leaders on a $15 an hour wage.

Leading the opposition to a raise has been the restaurant industry, which argues that requiring employers to pay more will lead them to cut jobs.

“As an industry of small businesses, any increase to the cost of labor — let alone a more than doubling of the federal minimum wage as some of these measures are calling for — will have a dramatic impact on a restaurant’s operations and ability to continue to create jobs,” said Christin Fernandez, a spokesman for the National Restaurant Association.

Most studies have shown that modestly raising the minimum wage has no effect, or only a small one, on job growth. Indeed, in 2006, Colorado passed a far bigger increase than the one it’s currently contemplating and saw no evidence of job losses as a result.

An array of evidence points to the issue’s political potency.

Last week, the National Employment Law Project (NELP) Action Fund, which has played a key role in the campaign for a $15 minimum wage, released poll results from seven states with competitive Senate races — Arizona, Missouri, New Hampshire, North Carolina, Ohio, Pennsylvania and Wisconsin. All seven state surveys found strong support for a minimum wage hike. And after respondents were informed that the Democratic candidate backs a raise while the Republican opposes one, all seven Democrats led in head-to-head polling.

To be sure, the Employment Policies Institute, an industry-backed group that opposes raising the wage, conducted its own surveys of those same states, using Google's consumer survey tool. It says it found that in all seven, 70 percent of likely voters said a candidate's opposition to a raise either would have no impact on their vote or would make them more likely to vote for the candidate.

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Still, NELP Action Fund hopes to use the Senate races to mobilize voters who back a wage hike, in order to boost the chances of a federal raise next year. The federal minimum is $7.25 an hour, and Congress hasn't raised it since 2009.

Celinda Lake, a prominent Democratic pollster, surveyed Colorado voters on the issue on behalf of the ballot initiative to raise the wage there. She, too, found high levels of support, especially among those who vote infrequently but support Democrats when they do — a sign that the issue could have the potential to lift turnout among Democratic voters.

And in 2014, voters in four red states — Alaska, Arkansas, Nebraska and South Dakota — approved minimum wage hikes even while overwhelmingly supporting Republican candidates.

Clinton has supported efforts to raise the wage and has backed a level as high as $15 per hour in certain places.

Donald Trump has expressed contradictory views on the issue during the campaign — at times saying he opposes any federal minimum wage at all, at others times saying he thinks it should be left where it is, and at still others saying he’d like to raised it to $10 an hour.