A preliminary injunction is an emergency court order that pauses a challenged action before the court issues a final ruling. It's governed by Rule 65 of the Federal Rules of Civil Procedure. To get one, a party must demonstrate four things: a likelihood of winning on the merits, a risk of irreparable harm without the order, that the balance of hardships tips in their favor, and that the public interest supports the relief.
Courts apply a "sliding scale" — the stronger the likelihood of success, the less irreparable harm the applicant needs to show. Preliminary injunctions are meant to preserve the status quo while a case proceeds, preventing harm that couldn't be undone even if the plaintiff eventually wins.
Preliminary injunctions have become one of the most powerful tools in modern litigation against government action. A single federal judge can freeze a nationwide policy, agency rule, or executive order. This power has generated debate over "nationwide injunctions" — orders from one district court that block government action everywhere, not just in that judge's jurisdiction.
Preliminary injunctions determine what policies are actually in effect while courts deliberate — a process that can take years. Because a single federal judge can block a national policy, these orders have become a primary check on executive power, and their use has accelerated sharply in recent administrations.
People often confuse a preliminary injunction with a final ruling. A preliminary injunction is temporary — it keeps things frozen while the case continues. The court can dissolve it at any time, and the eventual final ruling may go either way regardless of whether the injunction was granted.
Preliminary injunctions determine what policies are actually in effect while courts deliberate — a process that can take years. Because a single federal judge can block a national policy, these orders have become a primary check on executive power, and their use has accelerated sharply in recent administrations.
People often confuse a preliminary injunction with a final ruling. A preliminary injunction is temporary — it keeps things frozen while the case continues. The court can dissolve it at any time, and the eventual final ruling may go either way regardless of whether the injunction was granted.