Muslim candidates are facing personal attacks, religious discrimination and inflammatory accusations.
Democratic Senate candidate Abdul El-Sayed in Michigan has emerged as a major target of the campaign rhetoric, particularly from Trump.
Trump has repeatedly mocked El-Sayed’s name and said he hopes the candidate, if elected, will be subjected to metal detector checks before entering the Senate, using religiously charged insinuations to undermine his candidacy.
The attacks have extended beyond the US president, with Vice President JD Vance and El-Sayed’s Republican opponent, Mike Rogers, also accusing him of being a member of the Muslim Brotherhood.
Meanwhile, Ilhan Omar, a Muslim representative from Minnesota seeking re-election, has regularly faced accusations portraying her as anti-American and anti-Semitic, alongside attacks targeting her Somali background.
The growing use of anti-Muslim rhetoric has also extended to campaigns in which no Muslim candidates are running.
In Texas, Republican politicians have campaigned on a pledge to “fully ban Sharia Law in Texas”, turning hostility toward Muslims and their religious identity into an electoral issue.
Beyond elected officials, far-right provocateurs have also appeared at Democratic campaign events, shouting anti-Muslim slogans and contributing to an increasingly hostile political environment for Muslim Americans.
The rhetoric comes amid broader political polarization in the United States and growing criticism of the country's political establishment, whose campaigns increasingly rely on religious prejudice, identity-based divisions and inflammatory accusations.
Polling began at 6am local time (11:00 GMT) in New York, Connecticut, New Jersey, Virginia and parts of Indiana and Kentucky, with voting scheduled to begin at different times elsewhere in the country.