Yes. Nothing in the U.S. Constitution requires a particular voting method, and courts across the country have consistently upheld ranked choice voting. Federal and state courts have affirmed RCV in Maine, San Francisco, Cambridge, Minneapolis, and elsewhere.

• Baber v. Dunlap, 1:18-cv-465 (D.Me. Dec. 13, 2018) (upholding RCV in Maine)
• Dudum v. Arntz, 640 F.3d 1098 (9th Cir. 2011) (upholding RCV in San Francisco)
• McSweeney v. City of Cambridge, 665 N.E.2d 11 (Mass. 1996) (upholding RCV in Cambridge);
• Minnesota Voters Alliance v. City of Minneapolis, 766 N.W.2d 683 (Minn. 2009) (upholding RCV in Minneapolis)
• Stephenson v. Ann Arbor Bd. of Comm'rs, No. 75-10166 AW (Mich. Cir. Ct. Cnt'y of Jackson 1975) (Michigan district level court upholding RCV in Ann Arbor)

At the state level, Illinois home-rule communities have broad authority under the Illinois Constitution to determine the form and conduct of their own local elections. Several Illinois communities have exercised that authority by adopting ranked choice voting through local referenda.