SACRAMENTO, Calif. (Reuters) - Presidential candidate Elizabeth Warren would make it easier for employees to join unions and make rideshare drivers and other gig economy workers eligible for overtime, the latest effort by a Democrat to court the country’s deep-pocketed labor unions.

FILE PHOTO: U.S. Democratic presidential candidate Senator Elizabeth Warren (D-MA) responds to a question during a forum held by gun safety organizations the Giffords group and March For Our Lives in Las Vegas, Nevada, U.S. October 2, 2019. REUTERS/Steve Marcus

Warren’s plan, released Thursday in advance of an appearance before a labor group in Los Angeles, comes as she is catching up to frontrunner Joe Biden in the crowded field of 19 Democrats seeking their party’s nomination to take on Republican Donald Trump for the U.S. presidency in November 2020.

Organized labor, though greatly diminished in membership and power after decades of manufacturing decline and Republican-backed changes to state and federal employment laws, remains a potent force in U.S. politics, providing millions in donations and an army of grassroots volunteers to knock on doors and get out the vote for candidates that unions have endorsed.

With many union members defecting to vote for Trump in 2016, it is particularly important to Democrats to field a candidate who will win the support of labor organizations.

In her plan, Warren pledged to increase protections for home healthcare workers, a growing segment of the workforce, as well as immigrant employees who are undocumented. She would roll back Trump-era restrictions on the power of unions representing federal workers and work to restore public employee bargaining rights that have been reduced in several states.

Warren would end exemptions limiting the rights of domestic and farm workers and make it harder for companies to classify people as independent contractors instead of employees.

She promised to appoint judges to the U.S. Supreme Court who have records of supporting labor and would broaden employees’ ability to sue their employers.

Under her plan, companies with $1 billion or more in annual revenue would have to allow employees to elect 40% of the members of their boards of directors.

Because several Democratic contenders are strong supporters of labor, some already have plans that are similar to Warren’s.

Like Warren, for example, Biden and Vermont Senator Bernie Sanders would allow workers to unionize when a majority of a company’s employees sign cards saying they want to do that, rather than requiring them to also participate in an election.

Both senators also support eliminating so-called “right to work” laws at the state level, which allow employees to benefit from a union contract without paying union dues or being union members, among other reforms.

They also support rules to classify fast food chains and other franchisors as employers for the purposes of wages, benefits and collective bargaining, rather than considering workers to merely be the employees of the owners of individual franchise locations.

South Bend, Indiana, Mayor Pete Buttigieg has promised to guarantee gig economy workers rights as employees, including the right to organize, and offer preference in federal contracts to union employers.

California Senator Kamala Harris, who has benefited from labor support in the past and is also actively courting unions, has pledged to increase pay for teachers, among other pro-labor policies.

Biden condemns what he calls a “war on organizing, collective bargaining, unions and workers,” and has opposed “right to work” laws. However, his past support for free-trade policies opposed by unions has rankled some in the labor movement.

Warren was due to appear on Friday at a presidential forum by the Service Employees International Union in Los Angeles.