Could be anything from worn spark plugs to a bad distributor cap, bad rotor, bad 02 sensor, or bad ignition wiring.
I'd probably start with new spark plugs, distributor cap, and rotor. Three good plugs include the Autolite AP985 or Champion 3034, both of which are platinum plugs good for 100K miles, or the Autolite XP985 which will perform well for 200K miles. Gap them to .035. Try to find a distributor cap & rotor with brass contacts, that is better quality & will last longer than cheaper versions with aluminum contacts.
And if you haven't changed your ignition wiring in recent memory, I'd check it over for cracking or other signs of aging indicating it could be breaking down and in need of replacement. For the ignition wiring set, there is so much junk out there that I only recommend the OE Mopar replacement ignition wiring set.
If none of that helps, I'd think about replacing the upstream 02 sensor.