WASHINGTON — The Supreme Court on Friday handed a win to Republicans by ensuring that party committees paying for TV advertisements in the upcoming midterm elections can take advantage of the same discounts that candidates get.

The justices blocked a ruling by the Richmond, Virginia-based 4th U.S. Circuit Court of Appeals that had invalidated a recently announced Federal Communications Commission policy.

Only one member of the court, liberal Justice Ketanji Brown Jackson, objected to the majority’s decision.

The decision means that the often sharply discounted rates will apply to committees and candidates alike as litigation continues.

The National Republican Congressional Committee and the National Republican Senatorial Committee, with the backing of the Trump administration, had asked the Supreme Court to block the appeals court ruling.

In the unsigned order, the court said that the committees had shown they were likely to suffer “irreparable harm” if the appeals court ruling was not blocked because broadcasters have already started declining to offer them the discounted rates for ads.

Taken together with a Supreme Court ruling in June that lifted previous restrictions on committee expenditures, the latest decision represents a significant boon for Republicans.

In the June ruling, the Supreme Court struck down federal limits on “coordinated party communications,” caps that used to govern how much national party organizations like the Democratic and Republican Senate campaign committees could spend directly in concert with their candidates.

The two rulings allow Republicans to stretch their party committee dollars even further by allowing them to spend more committee money at lower rates. Democrats will have the same power, but the decision is of less help to them because their candidates are already, on the whole, better funded, and the Democratic National Committee has more than $100 million less in its coffers than the Republican National Committee does.

Several Democratic House and Senate candidates, including Sen. Jon Ossoff, D-Ga., challenged the March public notice issued by the FCC.

In an Aug. 25 ruling, the appeals court ruled that the party committees are not entitled to the same discounts as candidates.

Democratic candidates have generally raised significantly more money than their rivals for years, but Republican committees have far more money banked away for the fall, so the ruling allows the cash-flush GOP committees to help narrow that gap.