Is this really Donald Trump, or someone who is just using his name?
But consider this. The "donaldtrump" handle had a signup date of 10/28/2008, which was about a week before the Obama vs McCain election. He made three posts that day (probably to try it out) and then never posted again.
The real Donald Trump opened up his Twitter and Facebook accounts around the same time period. So he was definitely poking around social media at the same time the "donaldtrump" account was opened here.