Jamieson, Fausset and Brown on 2 Samuel 16:3

3. To-day shall the house of Israel restore me the kingdom of my father--Such a hope might not unnaturally arise at this period of civil distraction, that the family of David would destroy themselves by their mutual broils, and the people reinstate the old dynasty. There was an air of plausibility in Ziba's story. Many, on whom the king had conferred favors, were now deserting him. No wonder, therefore, that in the excitement of momentary feeling, believing, on the report of a slanderer, Mephibosheth to be among the number, he pronounced a rash and unrighteous judgment by which a great injury was inflicted on the character and interests of a devoted friend.

2Sa 16:5-19. Shimei Curses David.