The US Senate is debating the "SAVE America" bill, which would require presenting a passport or birth certificate when voting. Trump calls it his "number one priority," while Democrats consider it voter suppression and intend to block the initiative.

The bill proposes to change the voting procedure for federal elections by requiring voters to provide official documents such as a birth certificate or passport when registering and voting — meaning it will no longer be sufficient to simply check a box affirming citizenship, Euronews reports.

The bill aims to rewrite the National Voter Registration Act of 1993 and introduce civil and criminal liability for officials who register voters without the required documents.

The official justification is to prevent non-citizens from voting. However, statistics do not support this premise: over the past two decades, only 85 complaints have been documented involving people without American citizenship voting.

According to the Brennan Center for Justice, the bill could strip more than 21 million Americans who do not have easy access to the required documents of their ability to vote.

Some election law specialists call it the most restrictive measure Congress has ever seriously considered.