New York lawmaker Alexandria Ocasio-Cortez has criticised what she says are "unacceptable" lines at a number of polling stations in the city.
She said New York voters faced waits of between two and four hours before being able to cast their ballots in the November election.
"There is no place in the United States of America where two-, three-, four-hour waits to vote is acceptable," said the city's 14th congressional district representative.
Like thousands of other New Yorkers, Ms Ocasio-Cortez cast her ballot over the weekend as the state opened up a number of sites for early voting.
Nationally, some 60 million Americans have already voted due to the ongoing coronavirus pandemic and fears over potential delays to mail-in ballots.
In New York, Ms Ocasio-Cortez, 30, claimed the long queues were evidence of "voter suppression".
"And just because it's happening in a blue state, doesn't mean that it's not voter suppression," she told reporters outside a polling station in Parkchester on after casting her ballot on Sunday.
"If we are waiting three hours, four hours, five hours, if this was happening in a swing state, there would be national coverage."
It was not immediately clear if the congresswoman had any other evidence for her claims of voter suppression in New York, which is controlled by Democrats but governed by federal electoral authorities,
Ms Ocasio-Cortez also said the queues were evidence that early voting was working.
She added: "Frankly, this also shows the success of early voting as well. I will wait two hours just like my neighbours are."
Turn out at this election, described by many as the most important in living memeory, is expected to break US records.
And New York governor said that although he was not yet in possession of exact figures, "there was a tremendous number of people voting, which is very exciting.”
On Saturday - the first day of early voting - the New York City Board of Elections said 93,830 people cast their ballots, which was almost 50 per cent more than the total number for all nine days of early voting in the primaries in June.