Mary Kay Henry, the president of the Service Workers Worldwide Union, one of many nation’s largest and most politically highly effective labor unions, introduced Tuesday that she would step down after 14 years in her place.

Ms. Henry was the primary lady elected to steer the union, which represents almost two million staff like janitors and residential well being aides in each the private and non-private sectors.

Below her management, it launched a significant initiative generally known as the Combat for $15, which sought to prepare fast-food staff and push for a $15 minimal wage. Profitable over skeptics within the ranks, Ms. Henry argued that the union may make positive aspects by means of a broad-based marketing campaign that focused the trade as a complete fairly than particular person employers.

Labor specialists and trade officers cite the marketing campaign as a significant pressure behind vital minimum-wage will increase in states together with California and New York and cities like Seattle and Chicago. It additionally pushed a recent California law making a council to set a minimal wage within the fast-food trade, which is able to change into $20 an hour in April, and to suggest new well being and security requirements.

Ruth Milkman, a sociologist of labor on the Graduate Heart of the Metropolis College of New York, stated the union underneath Ms. Henry had been “prepared to take possibilities on fairly daring initiatives” and known as the Combat for $15 an “extraordinary achievement.”

However the marketing campaign has not unionized staff on a big scale and enabled them to barter collective bargaining agreements with their employers.

Ms. Henry’s tenure has coincided with a collection of legislative and authorized challenges to organized labor, together with state legal guidelines rolling again collective bargaining rights and permitting staff to decide out of once-mandatory union charges, in addition to a landmark Supreme Courtroom ruling permitting authorities workers to do the identical.

The union’s membership has stayed almost flat on Ms. Henry’s watch, whereas the general proportion of Individuals represented by unions has declined roughly 15 %. However the union misplaced necessary charges from greater than 200,000 nonmembers, inflicting a major lack of income.

The union will choose Ms. Henry’s successor by means of a vote of delegates at its quadrennial conference in Might.

“I’m able to cross the baton,” Ms. Henry, 66, stated in an interview. “S.E.I.U. is full of highly effective, dynamic, multiracial leaders of the subsequent era who’re able to seize this second of employee rebellion.”

The union’s second-ranking official, Secretary-Treasurer April Verrett, stated in an interview that she meant to be a candidate for the highest job.

A longtime organizer, Ms. Henry was an government vp when the union’s board selected her to fill out the presidential time period of Andy Stern, who resigned in 2010. She gained the primary of three full four-year phrases in 2012.

Ms. Henry’s strategy has invited criticism that the union is just too top-down in its efforts.

The organizer and scholar Jane McAlevey has criticized the Combat for $15 for being too centered on what she calls “mobilizing” — that’s, relying closely on knowledgeable workers, consultants and activists to generate consideration and form public opinion — fairly than constructing an intensive, worker-led group.

As S.E.I.U. obtained extra concerned in a union marketing campaign that an affiliate, Staff United, launched at Starbucks in 2021, some Starbucks staff stated decision-making and communications had change into extra centralized.

Within the interview, Ms. Henry rejected the competition that the union’s campaigns didn’t prominently contain staff, however stated it was vital to pair ground-level organizing with different methods that pressured employers.

The union has additionally been a pressure in politics and in coverage debates. Ms. Henry took the highest job shortly after President Barack Obama signed the Reasonably priced Care Act, which the union had mobilized to assist cross. She threw the union into defending the well being care laws towards Republican makes an attempt to repeal it.

The union’s political bets underneath Ms. Henry haven’t all the time labored out, like its endorsement of Hillary Clinton early within the 2016 presidential marketing campaign cycle. Many members later turned captivated with her Democratic major rival, Bernie Sanders.

In 2020, the union took a unique tack, laying out a coverage agenda that it urged candidates to embrace, which included making it simpler for staff to discount on an industrywide foundation and making massive investments in house care and little one care, together with elevated pay for care staff. Joseph R. Biden Jr. included most of the union’s concepts into his home coverage platform en path to the presidency.

“It’s an instance of how we take inventory and consider management selections, and draw classes and take into consideration what we need to do otherwise subsequent time,” Ms. Henry stated of the change in strategy.

Nonetheless, main house care and little one care measures proposed by Mr. Biden died within the Senate.

Ms. Henry stated the union was spending closely on this yr’s political elections — a sum prone to exceed $100 million, in response to a union official.

“We need to end the job,” she stated. “Now we have Senate targets, Home targets, governors, state legislators, metropolis councils — to make all the main positive aspects we are able to make.”