Chris Christie: What does he stand for?

This article is the latest in a continuing series examining where the 2016 candidates stand on five key issues. Click here to read about Jeb Bush, Hillary Clinton, John Kasich, Bernie Sanders, Scott Walker and Marco Rubio.

New Jersey Gov. Chris Christie once seemed like a formidable candidate for the 2016 GOP race. He's a Republican governor of a reliably blue state who took on unions and was re-elected with a sizeable margin in 2014. His tell-it-like-it-is style appeals to a class of voters who believe politicians are too cautious and beholden to public opinion.

Then the scandal over the lane closures of the George Washington Bridge engulfed his administration, driving down his once-stellar poll numbers. And the giant Republican presidential field means that there's more than one candidate who fits the bill for business-friendly moderate Republican (try former Florida Gov. Jeb Bush or Ohio Gov. John Kasich), as well as brash truth-teller (like businessman Donald Trump) - both constituencies Christie has sought to win.

His poll numbers have slipped in recent weeks, as Kasich and other underdogs like businesswoman Carly Fiorina have worked their way into the middle of the Republican pack, and it's not yet clear he's doing well enough to make it into the next GOP debate in September.

Christie has been campaigning hard in New Hampshire, banking on his efforts on the ground to win votes, telling CBS' "Face the Nation" earlier this month, "It's just work hard. That's what you have to do. And so we'll just continue to work really hard."

Here's a look at where Christie stands on the issues:

Education

Christie's high-profile battle with teacher's unions helped build his national reputation. He worked with the Democratic state legislatures to institute tougher tenure standards for public school teacher,s and he made it easier to fire ineffective teachers - reforms he'd like to replicate at the national level. Christie has also had several heated confrontations with teachers at town hall meetings.

At a GOP education summit earlier in August, he said that doing away entirely with teachers' unions would be "nirvana." He also recently said that unions deserve a "political punch in the face...because that's what they do to us," referring to the amount of money they've spent attacking his agenda.

Christie used to support the Common Core School Standards - New Jersey was one of the first states to adopt them. But earlier this year, Christie announced that he would instruct the New Jersey Department of Education to develop its own standards because Common Core was "simply not working."

He also advocates for more charter schools and school choice.

Christie's plans for college affordability include refocusing federal student assistance on students at the bottom of the economic ladder and forcing schools to itemize their tuition and separate educational expenses from the add-ons. He also wants to expand alternatives to student loans, to offer income-sharing agreements in which students promise to pay a portion of their future earnings over a certain number of years in exchange for private financing.

Additionally, Christie would create tax credits to finance programs that allow students to pay down their college debt by doing community service.

Immigration

Christie hasn't released a full plan to address immigration reform and enforcement yet, but there have been some glimpses of what he might do on the campaign trail and at home in New Jersey.

Over the weekend, he said the U.S. needed a system to track immigrants the way FedEx tracks packages, which drew some criticism. Defending his remarks on Fox News Sunday later, he said, "This is once again a situation where the private sector laps us in the government with the use of technology. Let's use the same type of technology to make sure that 40 percent of the 11 million people here illegally don't overstay their visas. If FedEx can do it, why can't we use the same technology to do it?"

Insinuating that he was comparing people to packages, he said, was "ridiculous."

He has called Democratic presidential candidate Hillary Clinton's support for a path to citizenship undocumented immigrants "extreme." Christie, who was recently interviewed on CBS' "Face the Nation," dismissed Republican frontrunner Donald Trump's plans to build a wall and deport millions of undocumented immigrants as "too simplistic."

In the same interview, he broke with some in his party by saying that he doesn't believe in changing the Constitution to end birthright citizenship, which Trump has promised to do.

In New Jersey, he signed a version of the Dream Act in 2013 that allows the children of immigrants who came to the U.S. illegally to pay in-state tuition at New Jersey colleges and universities, although the act does not allow them to receive financial aid. As recently as 2012, he opposed in-state tuition for the children of undocumented immigrants.

Economy

Christie's economic plan calls for a flatter, simpler individual tax code and a 25 percent corporate tax rate. He also calls for fewer regulations, like most Republicans, but has gone so far as to propose a requirement that for every new regulation imposed, one of equal cost be eliminated. He would also impose a cap on what businesses have to pay to comply with federal regulations.

His plans to reform Medicare, Medicaid and Social Security are among the most ambitious in the Republican field. Christie would alter the mild means testing that is currently in place, with wealthier Medicare recipients paying more of their premium costs on a sliding scale. Those at the top, making $196,000 or more, would pay 90 percent of their premiums out of pocket. Medicare retirement ages would also go up very slowly - by 2064, the eligibility age would be 69.

He wants to simplify Medicaid so that states would receive fixed amounts per enrollee, which, he said, citing the Congressional Budget Office, would reduce the deficit by $500 billion over the next decade.

By 2022, he would restructure Social Security so that it effectively becomes an insurance policy instead of an entitlement. He would gradually raise the retirement age to 69 and make the earliest retirement age 64. There would be a means test for people who make more than $80,000 a year in non-Social Security income, plus no Social Security at all for those who make more than $200,000 a year. The payroll tax could be entirely eliminated for those over 62 and under 25.

Other economic proposals include lifting the ban on crude oil exports and making the research and development tax credit permanent.

In 2012, Christie vetoed a bill that would have raised New Jersey's minimum wage from $7.25 to $8.50 an hour with annual adjustments for inflation. After that, Democrats in the state legislature put a referendum on the ballot and voters opted to increase it to $8.25 with automatic cost-of-living increases each year.

In a 2014 speech to the Chamber of Commerce, Christie said he was "tired of hearing about the minimum wage."

"I don't think there's a mother or a father sitting around the kitchen table tonight in America saying, 'You know, honey, if our son or daughter could just make a higher minimum wage, my God, all of our dreams would be realized,'" he said.

Social issues

Until 1995 - when he heard a heartbeat for his daughter, Sarah, during his wife's ultrasound - Christie considered himself pro-choice. Now he opposes abortion except for cases of rape, incest and the life of the mother.

He backs federal legislation that would ban abortion after 20 weeks, and he has advocated for policies like required parental notification, a 24-hour waiting period and a ban on partial-birth abortion.

He has also vetoed $7.5 million for family planning clinics, first saying they provided duplicative services and later saying he was specifically defunding Planned Parenthood. He has also pledged to defund the group at the federal level if elected.

When the Supreme Court legalized same-sex marriage in June Christie said, "Our job is going to be to support the law of the land and that, under the Supreme Court's ruling, is now the law of the land." He believes marriage is between a man and a woman and that any changes to that definition should be made "by a vote of the people, not by an act of a legislature, or Congress, or by a group of judges on a court."

As governor, he vetoed legislation that would have allowed same-sex marriage in 2012. He argued that voters should be able to decide the issue in a referendum. But when several judges ruled that marriage between gay couples should be legal in the state, he decided to drop the appeal he had promised. He did support giving same-sex couples rights through civil unions.

Foreign policy

Like many of his fellow Republicans, Christie said that President Obama "should have walked away" from the Iran nuclear deal his administration negotiated and is urging Congress to block it. He has also criticized the president's move to reopen diplomatic relations with Cuba.

For the fight against the Islamic State of Iraq and Syria (ISIS), Christie said on CNN's "State of the Union" in August that his "preferred alternative" is to arm regional partners including the Jordan, Egypt, the United Arab Emirates and Saudi Arabia to fight the group on the ground.

"They need more help. They need more help. They need better arms. They need more support from an intelligence perspective and they need to know that America's going to stand with them when the polls are up or down," he said.

He suffered a backlash after referring to the West Bank as the "occupied territories" during a speech in March - a term that some American Jews and parts of the Israeli government oppose - but has since taken steps to reaffirm his support for Israel. He has criticized the president for his handling of the U.S.-Israel relationship.

As a former prosecutor, Christie has also supported broad authorities for the National Security Agency and other government departments to collect information that could help stop terror attacks.

"I want to say that I think both the way President Bush conducted himself and the way President Obama has conducted himself in the main on those types of decisions hasn't been different because they were right and because we haven't had another one of those attacks that cost thousands and thousands of lives," he said in 2013.