Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) speaks during "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Attendees raise their hands at a rally for Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Subir Grewal, 43, from New York, shields his face from sun at a rally by Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) greets Democratic 2020 U.S. presidential candidate U.S. Senator Bernie Sanders (I-VT) during a "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) greets Democratic 2020 U.S. presidential candidate U.S. Senator Bernie Sanders (I-VT) during a "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) speaks at a "Bernie's Back" rally for Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

An audience member at a "Bernie's Back" rally becomes emotional as U.S. Rep. Alexandria Ocasio-Cortez (D-NY) speaks before Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) introduces Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) during the "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Filmmaker Michael Moore speaks at a rally for Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) introduces Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) during the "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) arrives to a "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) speaks during "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) speaks at a "Bernie's Back" rally for Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

An audience reflected in a teleprompter at a "Bernie's Back" rally listens to U.S. Rep. Alexandria Ocasio-Cortez (D-NY) speak before Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) introduces Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) during the "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) introduces Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) during the "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) arrives to a "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) speaks during "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

U.S. Rep. Alexandria Ocasio-Cortez (D-NY) arrives at a "Bernie's Back" rally for Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

An audience awaits Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) to speak during "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) addresses attendees during the "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) arrives to a "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

A supporter of President Donald Trump waves a slogan while awaiting Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) to speak during "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.

Democratic 2020 U.S. presidential candidate and U.S. Senator Bernie Sanders (I-VT) addresses attendees during the "Bernie's Back" rally at Queensbridge Park in the Queens Borough of New York City, U.S., October 19, 2019.