Julián Castro, Former Housing Secretary, Announces 2020 Presidential Run

Julian Castro at his announcement in San Antonio, Tex., on Saturday. Mr. Castro, the former secretary of housing and urban development, would be one of the youngest presidents if elected.CreditCreditIlana Panich-Linsman for The New York Times

Julián Castro, the former housing secretary and former mayor of San Antonio, announced on Saturday that he would run for president, one of the most high-profile Latino Democrats ever to seek the party’s nomination.

His first campaign stop will be in Puerto Rico, where he will speak on Monday at the Latino Victory Fund’s annual summit and meet with residents still struggling to recover from Hurricane Maria. Later in the week, his campaign said, he will go to New Hampshire.

“When my grandmother got here almost a hundred years ago,” Mr. Castro said at the Plaza Guadalupe amphitheater in San Antonio, in the neighborhood where he was raised. “I’m sure that she never could have imagined that just two generations later, one of her grandsons would be serving as a member of the United States Congress and the other would be standing with you here today to say these words: I am a candidate for president of the United States of America.”

Mr. Castro’s announcement had been expected for several weeks. He established an exploratory committee in December, two months after publishing a memoir, “An Unlikely Journey” — a familiar path for presidential candidates who want to play up their life stories and qualifications and, perhaps, get ahead of their biggest vulnerabilities. This month he also visited two of the early caucus and primary states, Iowa and Nevada.

He joins Senator Elizabeth Warren of Massachusetts, Representative Tulsi Gabbard of Hawaii, former State Senator Richard Ojeda of West Virginia and former Representative John Delaney of Maryland on the list of Democrats who have said definitively that they will seek for the party’s 2020 nomination. That list is expected to grow considerably in the coming weeks and months.

In his speech on Saturday, Mr. Castro emphasized education, calling for a national version of the prekindergarten program he established in San Antonio when he was mayor. To fund the program there, he increased the city’s sales tax — a politically risky proposition, especially in Texas, but San Antonio voters approved it.

His message was firmly progressive. He called for a higher minimum wage, denounced police killings of African-Americans, which he described as “state violence,” and embraced the Black Lives Matter movement. He also condemned President Trump’s immigration policy, including the practice of family separation and the proposed border wall, and declared that his first executive order if elected would be to rejoin the Paris climate accords, which Mr. Trump left.

George Rodriguez, a conservative blogger, talk-show host and Fox News contributor whom Texas Republican leaders designated as their spokesman on the announcement, said after the speech that the discussion of immigration had stood out to him. Mr. Castro, he said, did not “seem to be able to distinguish between legal and illegal immigration.”

Mr. Rodriguez also argued that the San Antonio pre-K program, which was one of Mr. Castro’s chief accomplishments as mayor, had duplicated existing programs like Head Start. “How much of an accomplishment that is is rather dubious,” he said.