http://www.slate.com/articles/news_and_politics/politics/2015/01/mitt_romney_s_reasons_to_run_the_former_republican_presidential_candidate.html

When Jeb Bush formed his leadership PAC, he said he wanted it to encourage other like-minded candidates. It worked. He encouraged Mitt Romney. The two-time presidential candidate is now seriously considering another run. “It’s real,” says a veteran of the last go-around. “He’s probably going to run.” When I asked another veteran of the Romney campaign, who spoke to the candidate this weekend, he explained why Romney had moved into high gear: “Bush stepped on the gas.”