The Defense Department is investigating Arizona Sen. Mark Kelly, a retired Navy captain, over “serious allegations of misconduct.” Defense Secretary Pete Hegseth said the investigation is related to a video featuring Kelly and other Democratic lawmakers appearing to encourage members of the military and intelligence community to defy illegal orders from the Trump administration. 

source https://www.nbcnews.com/now/video/defense-dept-to-investigate-sen-kelly-for-allegedly-telling-service-members-to-defy-illegal-orders-252886085882