The GOP asked the Supreme Court to scrap a Watergate-era rule preventing donors from bypassing limits on what they can give federal candidates.

The Supreme Court on Tuesday struck down federal limits on how much money political parties can spend in coordination with candidates for public office.

Roman Martinez, advocating to uphold the law, argued that ending the limits effectively legalizes quid pro quo political corruption, and that Vance’s claim is moot because the vice-president has “repe...