Sure you "Could".. You might not get in, as you probably "Should" not. You Should do as Tiger Paws said "dress in a manner that was fitting for the occasion. Anything less would be disrespectful"
I agree with Tiger Paws, dress to the occasion and if my team or organization was invited to the White House, I do not care who the President is, I would be there to support my team and or group.
Absolutely not. That would be completely disrespectful. I have more respect for our country, The White House, and the president--no matter who the president is. I would be in a suit and tie unless I was instructed to dress casually. I was brought up to dress appropriately for the situation.