The Supreme Court’s decision Tuesday blocking President Donald Trump from sending the National Guard into American cities is likely to raise a politically fraught debate about the president’s willingness to invoke a 19th century law to deploy the regular military on American soil instead.

Hundreds of thousands of Americans in rural and urban areas alike could see their votes rejected if the court decides that ballots must arrive by Election Day.

Ketanji Brown Jackson, associate justice of the Supreme Court, already granted an extension this fall on a filing date.