Just a day after conceding that he was unlikely to become the Democratic Party's presidential nominee, Bernie Sanders was back on the campaign trail. The morning session of the National Association of Latino Elected and Appointed Officials' annual D.C. conference was treated like any other candidate event, with Secret Service agents poring over the bags of lawmakers, and flanking the stage where Sanders -- introduced as a presidential candidate -- promised "brief remarks."

Over 20 minutes, the senator from Vermont recapitulated the main points of his campaign, honed after weeks of stumping for Latino voters in California. More than a few audience members hoisted their phones to livestream Sanders's pitch to "end private ownership of prisons and detention centers," to act on immigration reform by executive order if Congress did not and to defeat Republican Donald Trump.

"The American people in 2016 are not going to vote for a candidate who insults Muslims and Latinos and women and African Americans," Sanders said.

Sanders touched on only one issue he could directly affect in the Senate: Puerto Rico's $70 billion debt, and the Republican-led proposal to put the unincorporated U.S. territory under the control of a sort of emergency board.

"We are taking away virtually all of the political and democratic rights of the people of Puerto Rico," he said. "We are treating them as an absolute colony. We are giving them a financial control board, it will be a seven-member board, and four of those members. And from everything we understand, those four members will have unbelievable power over the people of Puerto Rico. They will be able to cut health care. They will be able to cut education. There is some discussion about even lowering the minimum wage."

For the past month, and even since he lost Puerto Rico's primary to Hillary Clinton, Sanders has been asking Democratic colleagues to abandon the Republican plan and instead support his alternative, which would require the Federal Reserve to buy Puerto Rico's debt.

"If the Federal Reserve could provide $23 billion in total loans with interest rates as low as 0.25 percent to the Arab Banking Corporation and central banks around the world eight years ago, it can facilitate an orderly debt restructuring for Puerto Rico," he wrote in a May 23 letter to senators.

At the NALEO conference, Sanders framed this as a moral choice. "Vulture funds have been buying up funds for pennies at the dollar," he said. "What they now want to do is get 100 percent of what the bonds are worth at very, very high interest rates. I believe it is immoral to give Wall Street speculators large profits literally on the backs of the poor and small children."

Neither Clinton, the presumptive Democratic presidential nominee, nor Trump, the presumptive GOP nominee, is scheduled to speak at the conference. Later Thursday, NALEO members will hear from Housing Secretary Julian Castro and Labor Secretary Tom Perez, both considered potential Democratic candidates for vice president. They also will hear from Libertarian presidential nominee Gary Johnson.