Why it matters
The dispute could shape congressional oversight and the work of federal agencies and businesses drawn into inquiries. It also raises the prospect of continued conflict between Congress and the executive branch.
What happens next
Democrats are expected to take control of Congress in January and have identified possible investigation targets. The scope and timing of any probes, and whether lawmakers pursue impeachment, remain uncertain.
Which investigations Democrats formally open after taking control in January
Whether the Justice Department takes any action involving lawmakers