Sen. Ted Cruz (R-Texas) said in a tweet Monday afternoon that he will file an amendment to the Senate immigration reform bill that would allow states to require identification for voter registration -- just hours after the Supreme Court struck down a law that did just that.

The Supreme Court struck down a 2004 Arizona law that required potential voters to submit proof of citizenship.

The Court ruled 7-to-2 against the law, and its decision was written by conservative Justice Antonin Scalia.

The amendment promises to be one of many contentious potential add-ons to the immigration bill. Cruz, one of the leading conservatives in the Senate, has come out against the bill.