Investigations into whether New Jersey Gov. Chris Christie had a role in causing traffic jams as political retribution could make advancing his agenda a challenge.

The Republican governor is finding some Democratic legislators are more likely to push back against his proposals and appointees because they see him as weakened by the scandal.

The uproar over the memo illustrates Christie’s struggles over the past month to regain his political footing amid a swirl of scandal. Until so-called “Bridgegate” erupted a month ago, he enjoyed a reputation as a politician firmly in control – of his well-honed public image, his second-term agenda in Trenton and the roadmap to the White House he intended to follow over the next three years.

The aura of authority surrounding Christie has given way to a feeling among his aides and allies that they are operating in new and unsettling territory, reacting to new twists in the scandal instead of driving events themselves…

“Assuming he is vindicated here, as I believe he will be, he could emerge from this stronger,” said GOP strategist Alex Castellanos. “If Christie’s political enemies miss, they will have inoculated him against these kinds of charges.”

But Castellanos added, “What he can’t endure is eight or 10 or 12 months of more shoes dropping, legal action, etc. If the faucet is still dripping in 2015, the party will move on.”

During the fall campaign, the liberal TV hero Rachel Maddow ran a stinging segment ridiculing The Star-Ledger’s endorsement of Gov. Chris Christie. How could we endorse him, she asked, when we criticized him so harshly in the same piece? Had we lost our minds?…

Yes, we knew Christie was a bully. But we didn’t know his crew was crazy enough to put people’s lives at risk in Fort Lee as a means to pressure the mayor. We didn’t know he would use Hurricane Sandy aid as a political slush fund. And we certainly didn’t know that Hoboken Mayor Dawn Zimmer was sitting on a credible charge of extortion by Lt. Gov. Kim Guadagno…

But be careful. Because if you turn your focus to the presidential race in 2016, you might wind up facing the same dilemma we did in the fall…

If one of the tea party favorites gets the Republican nomination, then the country is at risk. Because as we have just seen, one scandal can flip the board in politics. What if Hillary Clinton is the Democratic nominee, and some dark secret emerges about her tenure as secretary of state? How does President Rand Paul sound to you?

The fallout from the George Washington Bridge traffic debacle has opened the door for what might be the largest serious Republican presidential field in two decades. And that door is wide, wide open.

Politico Magazine asked some of the smartest and most experienced Republican operatives, pundits and even a former presidential candidate to weigh in on the suddenly unsettled field of 2016 GOP presidential aspirants. Three months ago, this conversation would have sounded like the Republican version of the Hillary chatter we’re hearing on the left today. Most of us would simply have cast Chris Christie as the inevitable nominee-in-waiting. No one can make that argument now, and the continued sell-off of Christie’s political stock has unlocked his formerly rock-solid donor base. It clearly tempts significant players to “buy the lottery ticket,” as Grover Norquist puts it.

If you ask me, Christie is almost dead but too stubborn to lie down.

The middle ground possibility – that Christie escapes being tied to the scandal personally, but it hamstrings his second term and gets painted as some sort of pattern – is perhaps the worst possibility for people considering backing Christie nationally, as it leaves him wounded but not fatally so.

The scandal is damaging to Christie in a couple of ways. The innocent explanation, that this was an unusual event resulting from a handful of ‘bad apples,’ still calls into question his management of personnel, a problem for a candidate running mainly on being an honest, competent executive who gets stuff done. And aside from its pure pettiness and how unnecessary the whole thing was (Buono was even more doomed than George McGovern in 1972), the use of government power to punish political enemies is especially problematic in a Republican primary because it’s precisely how Obama and the Clintons operate and have for years. And with the general electorate as well: Democrats are supposed to stand for giving particular people and groups stuff they want, so voters tend to forgive them – up to a point – when they hand out goodies to friends and punish foes. Whereas the point of electing Republicans is to stand up for the general interest – such as the interest in limiting runaway government spending and regulation – so voters tend to be harsher towards Republicans who act as if they were hired to give particular people and groups stuff they want.

But even if the Bridge flap proves a minor bump in the road for Christie’s national ambitions, it nonetheless reminds us that Christie is not only not the inevitable 2016 Republican nominee, he might not even make it as far as the Iowa Caucuses. And that perception itself can become self-fulfilling: it emboldens other candidates to jump in the race, as they might not if Christie looked like a juggernaut.

If Christie’s appointee David Wildstein is telling the truth when he claims evidence exists that proves the governor knew about the lane closures on the George Washington Bridge, and if that evidence is made public, then all the “Christie in 2016” talk is moot, because the governor will have great difficulty avoiding impeachment by the Democrat-controlled New Jersey legislature. If Wildstein is lying, Christie still has the headache of explaining why more than one of his trusted associates acted so vindictively and foolishly, and then tried to blame him.

Christie’s difficulties have caused some high-level Republican donors, bundlers, and party officials, as well as grassroots activists, to look around for a second option for 2016. No one is writing Christie off yet, but these people feel that the high stakes of the next presidential election require a backup plan. The name that is currently highest atop their list is that of Jeb Bush, former two-term governor of Florida and son and brother of presidents…

“Bush’s speeches are getting better, tighter, and more campaigny, from what I’ve noticed,” a senior Florida republican strategist says. “I still think Jeb is only a three-in-ten shot to go, but if you’re in his shoes, and Chris Christie has taken a huge hit in stock value — wouldn’t you wait and see? If Christie survives and runs, it’s a harder proposition by far, obviously.”

As Chris Christie’s star falls, the party is giving a second look to another brash blue-state governor who stared down unions at home: Scott Walker.

Republican strategists say no one is in a better position to get a boost from the Christie Bridgegate scandal than Walker, who stepped into the national spotlight in 2011 when he won a union-fueled recall election in Wisconsin…

“Many are looking at Walker because he has won in a blue state not through accommodation but by promoting and enacting policies consistent with conservative principles,” said Kevin Madden, a former aide to Mitt Romney during his 2012 presidential bid.

In the strongest indication that Christie has now won friends among former enemies, the Conservative Political Action Conference that previously snubbed Christie for being too liberal has invited him to speak at this year’s gathering…

While Christie is losing support among independents who previously supported him, he’s shoring up the very voters who might have opposed him in the primary — and he didn’t even have to change his politics to do so.

And if the over-hyped allegations prove fruitless over time, who’s to say he won’t be able to win those independents right back?

The left needs to slow its roll. Lest they want to end up like the boy who cried wolf — discredited and devoured by the zealousness of their own hype — Chris Christie’s opponents should sit back, relax and let this investigation play out.