Lawyers, teachers and politicians marched among thousands of demonstrators across the U.S. on Thursday to protest President Donald Trump's policies on immigration, the targeting of lawyers and judges, and the power of wealthy decision-makers.

Jennifer Vasquez Sura, whose husband Kilmar Abrego Garcia is a U.S. resident the administration sent by mistake to a prison in El Salvador, spoke at a Washington rally that was among the protests organized by lawyers' groups and by a coalition of more than 200 labor unions and immigrant rights advocates.

"He was illegally detained, abducted and disappeared by the Trump administration, though they admitted it was an error," Vasquez Sura said, adding that her husband has endured "50 days of suffering."

Organizers have accused the Trump administration of prioritizing profits for billionaires and called on it to invest in working families by fully funding healthcare, housing and public schools.

They expected hundreds of thousands of protesters across the country, hoping for the biggest May Day protests in U.S. history. Previous protests have garnered thousands of attendees since Trump returned to office.

Days after Trump celebrated his first 100 days in office with a campaign-style event in Michigan, the rallies came as Democrats sought a unified response and a galvanizing leader.

U.S. Senator Bernie Sanders of Vermont addressed thousands at a rally in Philadelphia.

In New York, U.S. Representative Alexandria Ocasio-Cortez warned protesters that Trump and the Republican majority in the U.S. Congress "are going after Medicaid next."

Ocasio-Cortez, who has been touring the country holding rallies with Sanders, said she had just learned that Republicans "have stopped and suspended next week's Medicaid cuts because they are getting too scared. But our fight is not over because they have only suspended" the cuts to Medicaid, the federal health insurance program for low-income Americans.

She said there were 6,000 protesters in New York City and tens of thousands more demonstrating in Philadelphia, Idaho, Los Angeles, Denver, Phoenix and Tucson, Arizona.

Also in New York, hundreds of lawyers attended a separate "National Law Day of Action" event, chanting, "Respect our judges, give support. Stand behind them, and the court."

Federal judges have claimed the Trump administration has failed to comply with court orders regarding foreign aid, federal spending and the firing of government workers. The administration disputes that it has defied judges.

Among the speakers in Manhattan was Stuart Gerson, who served President George H.W. Bush, a Republican, as an assistant attorney general and also served President Bill Clinton, a Democrat, as acting attorney general.

"This is about country, not about party," Gerson told the crowd, recalling what Bush told him when Clinton asked him to serve in his cabinet. "You don't pledge fealty to an individual, you pledge fealty to the Constitution."