Representative Alexandria Ocasio-Cortez of New York used her roughly 90 seconds on Tuesday night at the Democratic convention to nominate a fellow democratic socialist, Senator Bernie Sanders of Vermont, for the presidency and laud the progressive movement he had helped advance over the course of the race.

Ms. Ocasio-Cortez hailed “a mass people’s movement working to establish 21st-century social, economic and human rights, including guaranteed health care, higher education, living wages and labor rights for all people in the United States.”

The relatively small speaking role for Ms. Ocasio-Cortez, a huge young star in the Democratic Party, was disappointing to many of her admirers, especially given the swaths of time allotted on Tuesday night to lesser-known Democratic state officials and even Republicans like Colin L. Powell, the former secretary of state. But those officials had backed Joseph R. Biden Jr. in the presidential race, while Ms. Ocasio-Cortez was a staunch champion of Mr. Sanders.

Giving her a prominent role in the convention probably would have also provided grist for President Trump and Republican allies, who have sought to paint Mr. Biden as “the puppet” of left-wing Democrats like Ms. Ocasio-Cortez.

Her remarks were also a reminder that even as Democrats welcomed some Republicans like former Gov. John R. Kasich of Ohio and Mr. Powell to rally around Mr. Biden, the party was far from united around specific matters of policy, and the faction that had propelled Mr. Sanders to a leading candidate in the race early this year was still ardently behind his message.

Ms. Ocasio-Cortez had recorded her remarks last Wednesday, a spokeswoman said, days before Mr. Kasich sought to minimize her place in the Democratic Party, suggesting that the “outsized publicity” she received had disproportionately magnified her views. Hours before the convention kicked off on Monday, the congresswoman praised Mr. Kasich on Twitter for having “woken up &realized the importance of supporting a Biden-Harris ticket,” adding, “Something tells me a Republican who fights against women’s rights doesn’t get to say who is or isn’t representative of the Dem party.”

Although she never spoke Mr. Biden’s name in her remarks on Tuesday night, the congresswoman made clear with subsequent messages on social media for whom she planned to vote, issuing her “deepest congratulations” to Mr. Biden.

The following is a transcript of Ms. Ocasio-Cortez’s speech, as transcribed by The New York Times.

Alexandria Ocasio-Cortez: Good evening, bienvenidos, and thank you to everyone here today endeavoring toward a better, more just future for our country and our world, in fidelity and gratitude to a mass people’s movement working to establish 21st-century social, economic and human rights, including guaranteed health care, higher education, living wages and labor rights for all people in the United States.

A movement striving to recognize and repair the wounds of racial injustice, colonization, misogyny and homophobia. And to propose and build reimagined systems of immigration and foreign policy that turn away from the violence and xenophobia of our past. A movement that realizes the unsustainable brutality of an economy that rewards explosive inequalities of wealth for the few, at the expense of long-term stability for the many. And who organized a historic, grass roots campaign to reclaim our democracy.

In a time when millions of people in the United States are looking for deep systemic solutions to our crisis of mass evictions, unemployment, and lack of health care, en el espíritu del pueblo, and out of a love for all people, I hereby second the nomination of Senator Bernard Sanders of Vermont for president of the United States of America.

Isabella Grullón-Paz contributed reporting.