The National Republican Senatorial Committee and National Republican Congressional Committee asked the Supreme Court to halt a Fourth Circuit ruling that bars political parties from receiving the Federal Communications Commission’s lowest unit charge for broadcast advertising. The discounted rates apply during the 60 days before a general election, a period that opens this year on Friday, and the committees say they have already budgeted tens of millions of dollars in coordinated ad purchases. The FCC said in March that party committees were eligible for the rates when buying advertisements coordinated with candidates. The dispute follows the Supreme Court’s 6-3 June ruling striking down limits on coordinated spending between parties and candidates. Republicans are seeking to retain control of Congress in the November 3 midterms and held about $279 million in cash at the end of July across their three major national committees, versus roughly $136 million for Democratic counterparts, which also had nearly $18 million in debt.