210 lbs is a lot but 32 tires are wide. Check the tire manufacturers website and I would be surprised if they recommend more than 85 or 90 lbs max. What you want to do is ride with minimal rolling resistance and too much air pressure increases that.

Edit: Here's a good article on tire inflation. Check the chart near the bottom. So with a 250lb rider plus bike weight, 75 lbs of pressure is about right (of course this varies by tire manufacturer)

http://bccclub.org/documents/Tireinflation.pdf