There would be no effect at all. Even the Obama administration does not have something to say about bitcoin. Trump would not touch bitcoin knowing that he's more into envisioning larger things for the great 'ol America. His main concern is about keeping other nations off of his motherland. Anyways, bitcoin would still continue to move forward even with a president like him. As a businessman, he would pursue larger things other than the thriving bitcoin community and economy.
Yes, Trump does not need to touch bitcoin directly, but whatsoever action or inaction he takes concerning the economy would be immediately felt on bitcoin. If he makes real his campaign promises to make America great again, that would translate to a stronger dollar. With a stronger dollar, investors would have no choice than to throw their weight behind the dollar and bitcoin, most likely would get lesser attention, but if Trump failed to live up to his billing on the economy, bitcoin would be a major winner.