Republican presidential candidate Jeb Bush will unveil a national energy plan next week that is a key part of his pledge to spur 4 percent economic growth. The plan, which Bush will detail at a natural gas company near Pittsburgh, is the latest roll-out from the former Florida governor as he attempts to sell himself to voters as the policy heavyweight in the field and steer clear of the personal battles that have erupted in the nomination race as Donald Trump has risen in the polls.