A Supreme Court principle is being put to the test by President Donald Trump's emergency appeal. This principle, known as the Purcell principle, is intended to prevent last-minute changes to voting rules that could cause chaos before elections. The principle has been in place for 20 years and is rooted in a 2006 Supreme Court decision.

It has never been applied to a federal election policy like the one in question, which involves screening state voter rolls. Further details on this developing story are available from KVIA ABC-7's source, CNN. The outcome of this case could have implications for how the court handles future election-related litigation.