Chris Christie’s “bridgegate” scandal had such an impact on the emerging 2016 GOP primary field not only because Christie was considered the early frontrunner but because of why he was considered the frontrunner. In addition to his advantage as a governor and his success in getting Democratic and minority votes, Christie was the 2016 candidate who was moderate enough to win prominent establishment backing but still conservative enough to envision winning the nomination.

Thus while the primary fight would no doubt be bruising, it was conceivable that the other categories–libertarian, religious conservative, defiant conservative firebrand, etc.–would be represented by more than one candidate and split the remaining vote. Christie, then, had both no competition and too much competition. I think this scenario always overestimated Christie’s odds at winning the nomination because at some point the competition would thin out and supporters would coalesce around fewer candidates, but there’s no question it made him a strong contender.

If Christie is no longer the frontrunner, that means there’s an opening for a “moderate” with conservative credentials. And that, in turn, means we’ll have a resurgence in speculation over whether Jeb Bush will run. Politico catches the latest, which was Bush’s radio interview yesterday mulling it over:

Former Florida Gov. Jeb Bush says he will make a decision on whether to run for president in 2016 at “the right time” — later this year.

“I don’t wake up each day saying, ‘Now what am I going [to] do today to make the decision?’ I’m deferring the decision to the right time, which is later this year,” Bush said in an interview Wednesday with Miami CBS affiliate WFOR.

The brother of former President George W. Bush and son of former President George H.W. Bush said he will make up his mind based on whether he can run an uplifting campaign.

Jeb Bush is also pushing back, ever so diplomatically, against his mother’s comments last year that “there are other families” besides the Bushes, and it’s time to give someone else a turn. After Jeb’s brother, George W. Bush, was asked about the comments by Jay Leno (and said his brother would make a great president), CNN quoted Jeb’s response: “Even when I was a teenager, I’d listen to her respectfully and never always followed what she said, even though she was probably right. And now at the age of 60, I really feel I don’t have to listen to every word she says,” he said, drawing laughs. “At some point you got to make these decisions like a grown up.”

But his name came up on Leno’s show again this week, in a more positive mention:

Republican Speaker of the House John Boehner made his first ever appearance on “The Tonight Show With Jay Leno” on Thursday, just to get some facetime with Leno before he leaves the show on Feb. 6. …

Asked what he thought of the upcoming presidential race in 2016, Boehner said, “I’m not endorsing anybody. But Jeb Bush is my friend and, frankly, I think he’d make a great president.”

Jeb Bush not only has the gubernatorial success and moderate credentials to match those of Christie, but he is also thought to have the crossover appeal to voters outside the GOP’s traditional support blocs that Christie does. So it’s reasonable to assume that Bush, who in fact has picked fewer fights with the grassroots than Christie has, could step into Christie’s shoes. But does that make him, like Christie was thought to be, the frontrunner?

Probably not, because Bush’s path to the nomination would be complicated in a few ways. The most obvious is his last name, and the GOP, with a bevy of young stars, will probably only be more hesitant to nominate Bush now that it appears Hillary Clinton is the Democratic frontrunner. One advantage Republicans would have over Clinton is that she represents a bygone era both for the country in general and the Democratic Party in particular, having already spent eight years in the White House of a president with a very different political agenda than the one she served as secretary of state. It’s doubtful the grassroots, so opposed to the GOP’s history of next-in-linism, would be satisfied with a Bush-Clinton election.

Additionally, Christie wasn’t the only prospective candidate standing in Jeb Bush’s way. The general consensus was that either Bush or Marco Rubio would run in 2016, but not both. They served the same state and would thus split their constituency, most likely ensuring neither would win. Would the party prefer to run Jeb or Rubio? The latter seems the better bet at this point.

Competing with the senators won’t be easy, considering Rand Paul’s popularity and Ted Cruz’s Texas network. And the governors, like Scott Walker and Mike Pence, would thrive against a wounded (or absent) Christie. Luck has never been on Jeb Bush’s side with regard to the presidency: no one doubts his qualifications, experience, intelligence, diligence, or sense of service, to say nothing of his accomplishments in office in areas like education reform. But even with Christie weakened by bridgegate, his path to the presidency is strewn with roadblocks.