U.S. President Barack Obama speaks as he is joined by representatives and community members from San Antonio, Philadelphia, Los Angeles, Southeastern Kentucky, and the Choctaw Nation of Oklahoma during an East Room event January 9, 2014 at the White House in Washington, DC. President Obama announced the five areas as his administration's first five "Promise Zones" to help the local communities "to create jobs, increase economic security, expand access to educational opportunities and quality, affordable housing and improve public safety." Sen. Rand Paul, R-Ky., speaks to members of the media after an East Room event that President Barack Obama announced San Antonio, Philadelphia, Los Angeles, Southeastern Kentucky, and the Choctaw Nation of Oklahoma as "Promise Zones" on Jan. 9, 2014 at the White House in Washington, D.C. (credit: Alex Wong/Getty Images)

CONCORD, N.H. (AP) — As Democrats intensify their probe in New Jersey, Gov. Chris Christie has found little support — and sharp criticism in some cases — from the slate of potential rivals for the Republican presidential nomination. At the same time, would-be allies from key states have been slow to rally behind the Republican governor, whose administration appears to have created a massive traffic jam to punish a political adversary.

Some Republican leaders in Iowa and New Hampshire — states already gearing up for the nation’s first 2016 presidential nominating contests — offered only conditional support for Christie, acknowledging the New Jersey investigation is far from over.

“I think only time will tell on this,” said Bruce Rastetter, a wealthy Iowa businessman who led a group of like-minded Republican donors to New Jersey to encourage a 2012 Christie presidential run. “And if he didn’t have any knowledge, he should have a future.”

Documents revealed last week that figures in the Christie administration may have intentionally caused major backups near the George Washington Bridge, linking the community of Fort Lee to New York City, to exact political retribution against a Democratic mayor who refused to endorse his re-election campaign. Christie fired a top aide and jettisoned his chief political adviser after internal communications confirming their involvement became public.

He adamantly denied any personal “knowledge or involvement” in the lane closures.

Democrats in New Jersey on Monday formed special legislative committees with subpoena power, expanding the traffic-jam investigation into an abuse of power probe. But Christie, who is considering a presidential bid, is also facing criticism from his own party — particularly from other Republicans who are eyeing the presidency.

The intense scrutiny underscores the tremendous political pressure Christie faces as one of his party’s most popular figures ahead of the 2016 presidential contest.

“Nobody likes the idea of using government against someone for political reasons,” Kentucky Republican Sen. Rand Paul, who is examining a 2016 run, said in an interview with KPNX-TV in Phoenix. “I think that’s what’s being addressed here and that’s why I think it’s a bigger issue than just traffic. Because if it is true, if it looks like someone who won an election is punishing people they beat in the election; that leaves a really bad taste in people’s mouth.”

Former Pennsylvania Sen. Rick Santorum, weighing a second presidential candidacy, complimented Christie on Sunday for taking tough questions but raised new questions about the governor’s staffing decisions.

“The people that you hire are the policies that are implemented,” Santorum said. “It’s very clear that the personnel there was not sensitive to what seemed to be a fairly obvious wrong thing to do.”

Other prospective Republican presidential candidates simply declined to support Christie in recent days when given the opportunity.

Wisconsin Rep. Paul Ryan said he didn’t “have any thoughts” on Christie’s situation when asked after a Monday speech. “I’ve been busy doing my job,” Ryan said.

Wisconsin Gov. Scott Walker said last week that he didn’t know enough about the situation to comment. He has remained silent in the days since details emerged. Florida Sen. Marco Rubio said Sunday that people should “reserve judgment” on Christie, but he largely avoided the topic.

On the ground in New Hampshire, a state known to make or break presidential candidates, state GOP chairwoman Jennifer Horn said that Christie “demonstrated leadership by taking responsibility.” But other Republicans suggested Christie’s denials could have longstanding consequences.

“I take him at his word that he didn’t know,” said Michael Dennehy, a veteran of Republican presidential politics. “That being said, it should be of serious concern there was such nonsense going on behind his back without him knowing. That is, and should be, of great concern for anyone looking at him as a possible presidential candidate.”

A sample of party leaders in Iowa say the New Jersey governor is far from damaged goods, but only if nothing further emerges. Christie remains popular in Iowa with Gov. Terry Branstad and Lt. Gov. Kim Reynolds, expected to run for re-election this year. Reynolds said Christie would be welcome to campaign for the duo.

“I think Iowans and I think individuals across this nation respect somebody that’s willing to stand up apologize, take responsibility, take action,” Reynolds said. “And, as long as they are not able to tie him to anything – if this is accurate, and I believe it is – then, he’ll be fine.”

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