New Jersey Gov. Chris Christie (R) is continuing a comeback of sorts. As the Wall Street Journal reported, “Christie scored a political win Monday with the passage of bills overhauling the state’s bail system. It was a bipartisan victory years in the making that came as the Republican governor has begun to emerge from a challenging time. The Democrat-led Assembly returned to Trenton from summer break to pass legislation that will have voters decide in November whether to amend the state Constitution to deny bail to defendants seen as a threat to public safety. The bill passed 60-0, with eight abstentions. A companion piece of legislation would allow low-level offenders who can’t afford bail to avoid jail if a pretrial program determines they aren’t a safety or flight risk. It passed 53-7 with nine abstentions.”

This victory comes at an auspicious time. The bridge scandal hovers — albeit much less conspicuously — and Christie received criticism for not fully funding the state pension system. Christie nevertheless is traveling widely and raising plenty of money on behalf of the Republican Governors Association. His poll numbers have stabilized, and he remains at the top of at least one 2016 poll, providing some reassurance to prospective donors.

It is not clear that Christie still will make a presidential run. But if he does want to pivot toward a presidential campaign, several things need to occur.

First, at some point he will need a clean bill of health on the bridge scandal. Donors and GOP voters are not going to gamble on a presidential candidate who could face a finding of wrongdoing or even legal action at any time. This one is largely in the hands of Democratic legislators and prosecutors, all of whom are going to operate on their own timetable.

Second, Christie will be hard-pressed to win over (or win back) donors if Jeb Bush runs. Bush generates great affection and respect among the donor class and many moderate Republicans. With some re-evaluation of George W. Bush’s presidency and the passage of time, the Bush name may no longer be a barrier. Will Jeb Bush run? I’d put the odds at 50-50, but we won’t know for sure until the end of the year, when he said he would make his decision. (It is noteworthy, however, that while Christie is out on the stump for 2014, Bush has not been.) And, yes, Mitt Romney will have to keep reiterating that he is not interested in another presidential run — a run that might divide support among GOP moderates and big donors. Once again, these factors are not within Christie’s control.

What is in Christie’s control is formation of a presidential-caliber message and agenda. This is almost the most critical factor for a successful run. It is not enough merely to present oneself as a generic bipartisan governor. Primary voters will want to know what Christie stands for. Bipartisanship must be a means to an end for these voters — successful conservative governance and re-establishment of U.S. influence in the world. The longer Christie delays spelling out what he is for on a national agenda, the more conservatives will be suspicious that he doesn’t have firm objectives and strong conservative instincts. This is not unlike the problem Texas Gov. Rick Perry (R) faced in 2012: how to translate success on the state level into an argument for “promotion” to the presidency.

Will Christie be the messenger for the reform conservative agenda? Will he focus on one part of that, namely Rep. Paul Ryan’s anti-poverty policies? Whatever Christie decides, he will have to make a convincing case for the message and for himself as the best messenger to win and enact that agenda. (If he’s not, why not get someone else who also can adopt a reform conservative agenda?)

Equally important, Christie will need to define his foreign policy vision and become conversant in national security issues. He stumbled earlier by referring to the “occupied territories” in front of a staunchly pro-Israel group. Although he has given a few foreign policy speeches, he has yet to offer a comprehensive critique of what the president has done wrong and what he would do differently. (He previously dismissed, unwisely in our view, the debate between Sen. Rand Paul (R-Ky.) and Perry over the direction of foreign policy as mere squabbling.) He may want to use his expertise and experience as a federal prosecutor and as a governor with complex home security issues, but in and of itself this won’t be enough. The more chaotic the world becomes, the more essential it will be for presidential candidates to present themselves as capable and plausible commanders in chief.

Christie certainly can make a run if he chooses. But to do so successfully, he will need some luck and a first-rate agenda. That’s pretty much true of all the candidates, come to think of it.