After being hospitalized for a heart attack, Sen. Bernie Sanders officially returned to the campaign trail on Saturday in New York for a rally with Rep. Alexandria Ocasio-Cortez.During the rally, AOC gave her official endorsement to Sanders, which may be the most sought after endorsements among progressive supporters of the Democratic party. "It wasn't until I heard of a man by the name of Bernie Sanders that I began to question and assert and recognize my inherent value as a human being who deserves health care, housing, education and a living wage," Ocasio-Cortez said in her speech, where she also called for the "mass mobilization" of young, working class voters in the upcoming 2020 election. The rally came just days after Rep. Ilhan Omar of the "Squad," announced her endorsement of Sanders. Rep. Rashida Tlaib is also set to announce her support of the Vermont senator within the next few weeks. During Omar's announcement, she hinted that Sanders' criticism of Israel drew her to his campaign.The event was held at the Ravenswood Generating Station, to which AOC called the site "ground zero in our fight for environmental justice." The power plant is also next to the biggest public housing development in the US and Bernie explained that his Green New Deal would help fight "environmental racism" like the one he claims is seen in this area. Sanders explained during the rally that the proximity of the power plant to the largest public housing development in the US was an example of "environmental racism" and his Green New Deal was here to help combat the problem. "I've been around politics a few years and it is hard to believe the degree to which in less than one year, this woman, the youngest woman ever elected to Congress, it is hard to believe the degree to which she has transformed politics in America," Sanders said, praising the young representative. AOC called Sanders while he was still in the hospital to tell him he had her endorsement. His campaign is hopeful that her decision will help with the stalemate the campaign is going through in the polls according to CNN. During the "Bernie's Back" rally, Sanders' wife also spoke declaring her husband healthy and "more than ready to continue his life-long struggle to fight for the working people of America."