Democratic presidential candidate Kamala Harris unveiled a plan to crack down on pharmaceutical companies which overcharge for prescription drugs, making her the latest 2020 White House candidate to seize on the issue.

Harris, a U.S. senator from California, said her proposal would dramatically lower drug costs by allowing the federal government to set fair prices for what companies can charge and forcing them to pay rebates to consumers for medicines sold at artificially high rates.

With the high cost of drugs and rising healthcare rates a pressing issue for voters, debate over the future of the U.S. healthcare system has become a focal point of the Democratic nominating contest.

Democrats exploited the issue in last year’s midterm congressional elections and believe it helped them regain control of the U.S. House of Representatives from the Republican Party.

Harris’ proposal follows plans by several of her Democratic rivals to lower drug costs, an issue they are keen to exploit after Republican President Donald Trump backed down this month from a policy aimed at getting drug companies to lower costs.

Former Vice President Joe Biden, who leads the more than 20 candidates seeking the Democratic presidential nomination, touted a plan at a forum on Monday that would repeal the law that prohibits Medicare from negotiating lower prices with drug companies.