Something plainly has changed for Jeb Bush. The Tampa Bay Times has noticed the change. Alex Leary reports: “Two appearances last week in starkly different settings — a black-tie dinner Monday in Manhattan and a commencement address Saturday at the Christian college that bears this town’s name [Grove City, Pa.] — suggest that the former Florida governor is summoning the energy and exposing his strengths and weaknesses for a 2016 campaign.” He certainly is raising his profile and sharpening his message. (“Bush remains serious but undecided, according to close friends and advisers, but his conspicuously busy schedule increasingly resembles a pre-campaign, replete with informal outreach to donors and intimate talks with key religious leaders.”)

In a matter of months, Bush has gone from a “long shot” to “more likely than not” to run. As with many political developments, a possible Bush run was carried along by a mixture of luck and good timing. First, whether he is temporarily or permanently derailed, New Jersey Gov. Chris Christie’s bridge scandal unnerved donors and mainstream Republicans, prompting them to look at least for an alternate should a Christie run become impossible. The more they looked around and the longer the bridge scandal cloud hovered over Christie, the more the search for a backup became a search for a replacement for the can-do Republican with broad appeal. At the moment Christie supporters became unnerved, no current governor immediately stepped forward as the reassuring grown-up to capture those shopping for another candidate. Republican Govs. Rick Snyder of Michigan, John Kasich of Ohio and Scott Walker of Wisconsin naturally were focused on their own reelection races, while Rep. Paul Ryan (R-Wis.) showed no real interest in a presidential run.

But there was Bush, with 100 percent name recognition and no reelection campaign to keep him busy back home. The more the buzz over Bush built, the more he began to take it seriously. And before you knew it, there were a whole lot of Republicans interested in a potential candidate who was interested enough to bolster his profile, reach out to factions of the party and enunciate a message.

Bush’s ascent up the list of top-tier, probable candidates was further aided by potential opponents’ unsettled personas and fuzzy messages. We know Sens. Rand Paul (R-Ky.) and Marco Rubio (R-Fla.) are considering  a run, but what would they want to run on — what agenda or message are they presenting? Paul alternates between libertarian extremist and right-wing Republican. Business leaders and mainstream Republicans see in him too much of his father, Ron Paul, and not enough experience or discipline to make the freshman senator a realistic choice. Rubio is the eloquent pol with a heart-warming immigrant story, but is he running as the grown-up on foreign policy and education or the bomb-thrower who championed the shutdown? Bush, meanwhile, is a known quantity who can skip the introductions and get to the substance of what he wants to accomplish on education and immigration reform. While opponents are figuring out who they want to be, Bush is talking about what he wants to do.

Other candidates certainly may come along. If they are mature people with something to say, they will rise to the top tier. And certainly, Bush may not run, or if he does, he may not be a shoe-in. But right now, potential supporters know who he is and what kind of message he will be presenting. That is more than you can say about a lot of the 2016 contenders.