It can be done -

Check in deadline for domestic flights is 15 minutes before departure. So you have 65 minutes to deplane, walk to immigration, go through immigration, pick up bags (usually quick), go through customs and get to the check in desk for your domestic flight...

Normally I would estimate 40 minutes for all of that. Immigration is the step which usually takes the longest. So.... yes .... if there are no surprises then you will be OK.

However, if your flight should arrive slightly late or if you should find yourself at the back of an enourmous line of people at the immigration counters, then you will need to be pushy. Explain in a loud voice that you have a domestic connection which departs in 30 minutes and please, please, could people let you jump to the front of the line... (but stay calm and polite, because airport officials tend to dislike anything that looks unorthodox).

I think you'll find that quite a few people on this board have had to ask a special favour of the people ahead of them in a line at some stage in their travels. Even though nobody likes to be asked to cede their position at the head of the line and wait a little longer, I think most people can appreciate that they may find themselves with a tight connection one day and they may be the one asking to jump the queue...

ALSO - If you have the luxury of being able to travel with hand luggage only, you can often speed through airports much faster than the folks who have to wait at the carousel and then find that they're third in line for customs.