Additionally, it's important to take into account the starting surge of the air conditioner, which can be several times higher than the running wattage. A 2000-watt generator may be able to start an air conditioner with a starting surge of up to 3000-3500 watts, but it will need to be properly sized to handle the sustained load of the running air conditioner.
It is also important to note that the wattage rating of the generator is not the only factor to consider. You will also need to take into account the surge wattage (or inrush current) of your air conditioner. This is the maximum amount of wattage your air conditioner will draw when it first turns on. Your generator will need to be able to provide enough power to cover both the running and surge wattage of the air conditioner. If you are not sure what the surge wattage is for your air conditioner you should consult the user manual.
If you are not sure if a 2000-watt generator will be able to run your camper air conditioner, it is always a good idea to consult the manufacturer's recommendations or a qualified electrician.