My previous "mEan TwEEtS" comment was a joke. Mean tweets don't mess up America. (in any notable way)
Tweets do have the capacity to be offensive: making fun of people with disabilities, cursing at someone, etc., but it is much better to have a president who doesn't know how to behave on social media than to have a president who will ruin the economy, start unnecessary wars, depend on other nations (especially nations like China), open the U.S. border illegal immigration, and other bad things.