(Credit: C-SPAN.org)

Author's note: The reader will notice that some of the differences between Barack Obama in 2008 vs 2012 are actually from 2007. As presidential campaigns begin to last two years, statements made in 2007 are relevant because they are closely related to the 2008 campaign.

1. The president cannot go to war without Congress

In a 2007 questionnaire for the Boston Globe, then-Senator Barack Obama replied:

The President does not have power under the Constitution to unilaterally authorize a military attack in a situation that does not involve stopping an actual or imminent threat to the nation.

In 2007, Obama also supported the War Powers Act, passed in 1973 with the stipulations that Congress must be notified within 48 hours of committing armed forces and that a declaration of war must be made within 60 days:

We thought we had learned this lesson after Vietnam. After Vietnam, Congress swore it would never again be duped into war and even wrote a new law, the War Powers Act, to ensure it would not repeat its mistakes.

By 2011, President Obama committed air power to aid the rebels fighting Moammar Gaddafi. An administration report justified the action without congressional approval on the grounds that it was not a war, but "kinetic military action":

US operations do not involve sustained fighting or active exchanges of fire with hostile forces, nor do they involve the presence of US ground troops, US casualties or a serious threat thereof, or any significant chance of escalation into a conflict characterized by those factors.

Despite no legal consultation on the administration's actions and more than 60 days later, White House Press Secretary Jay Carney told the media, "I'm not aware of any special seeking of guidance...We believe we are acting consistent with the War Powers Resolution."

2. Debt Ceiling

Running against the Bush record in 2008, Obama said:

The way Bush has done it over the last eight years is to take out a credit card from the bank of China in the name of our children, driving up our national debt from $5 trillion for the first forty-two presidents. Number Forty-Three added $4 trillion by his lonesome so that we now have over $9 trillion of debt that we are going to have to pay back. $30,000 for every man, woman, and child. That's irresponsible. That's unpatriotic.

In the summer of 2011, Carney said of Obama in 2008 vs 2012:

The president...regrets that vote and thinks it was a mistake. He realizes now that raising the debt ceiling is so important to the health of this economy and the global economy that it is not a vote that, even when you are protesting an administration's policies, you can play around with and you need to take very seriously the need to raise the debt limit so that the full faith and credit of the United States government is maintained around the globe.

3. Iraq

As far back as 2002, then Illinois State Senator Barack Obama opposed a potential war in Iraq. In a 2008 New York Times op-ed, Obama prescribed:

We can safely redeploy our combat brigades at a pace that would remove them in 16 months. That would be the summer of 2010 - two years from now, and more than seven years after the war began.

Combat troops were not officially redeployed and the Iraq war officially over until December 2011, as set up by the Status of Forces Agreement (SFA) negotiated by President Bush shortly before leaving office. As president, Obama attempted to renegotiate the SFA to allow American troops to remain in Iraq, but his proposal was rejected by Prime Minister Nouri al-Maliki.

4. Gay Marriage

As early as the 1990s, Obama favored gay marriage - well before gay marriage was on the national radar - but changed his mind by the time he ran for the US Senate in 2004. In his 2008 appearance at Pastor Rick Warren's Saddleback Civil Forum on the Presidency, Obama said, "I believe that marriage is the union between a man and a woman." In 2012, Vice President Joe Biden endorsed gay marriage on "Meet the Press." President Obama followed up by saying that he had already made the decision to support gay marriage, but was waiting until the Democratic National Convention to announce it.

5. Guantanamo Bay

Throughout 2007 and 2008, Obama repeatedly endorsed his intention to close the prison facility at Guantanamo Bay, Cuba. After his election, in an interview with Steve Kroft on "60 Minutes," Obama reiterated his intention, "I have said repeatedly that I intend to close Guantanamo and I will follow through on that."

On January 22, 2009, in one of his first acts as president, Obama signed an executive order that stated:

The detention facilities at Guantanamo for individuals covered by this order shall be closed as soon as practicable, and no later than one year from the date of this order.

Almost two years after, the deadline has passed, the controversial facility is still open and, in the summer of 2012, the Obama administration issued an executive order prohibiting contact between detainees and their lawyers.

6. Patriot Act

Of one of the more controversial enactments of the Bush administration, Obama said in 2007:

I will provide our intelligence and law enforcement agencies with the tools they need to track and take out the terrorists without undermining our Constitution and our freedom. This means no more illegal wiretapping of American citizens, no more national security letters to spy on citizens who are not suspected of a crime. No more tracking citizens who do no more than protest a misguided war. No more ignoring the law when it is inconvenient.

In addition to extending the Patriot Act in 2011, which included the roving wiretap provision, President Obama's Departments of Justice and Homeland Security have released reports identifying certain single-issue and, commonly, right-wing groups such as pro-life activists, veterans, and activists for the Second Amendment, as potential terrorists or those who might be recruited by domestic terrorists.

7. War on Drugs

Obama, who has admitted to recreational drug use in his youth, supported marijuana decriminalization in his 2004 US Senate campaign, and seemed reluctant to go after medical marijuana users in a Rolling Stone interview saying, "I would not have the Justice Department prosecute and raid medical marijuana." To a questioner in New Hampshire in 2007, Obama restated, "I would not have the Justice Department prosecute and raid medical marijuana users."

However, numerous distributors of medical marijuana have been raided, such as Chaddwick McKeen of Orange County, California, where holders of medical marijuana cards are protected. Explaining himself, Obama in 2008 vs 2012: "What I specifically said was that we were not going to prioritize prosecutions of persons who are using medical marijuana." However, through early 2012, Obama was on pace to exceed President Bush's total of medical marijuana raids.

8. Signing Statements

As a candidate, Obama criticized President Bush for his use of signing statements. In an installment for the Boston Globe in 2007, Obama said of signing statements:

While it is legitimate for a president to issue a signing statement to clarify his understanding of ambiguous provisions of statutes and to explain his view of how he intends to faithfully execute the law, it is a clear abuse of power to use such statements as a license to evade laws that the president does not like or as an end-around provisions designed to foster accountability. I will not use signing statements to nullify or undermine congressional instructions as enacted into law.

In March 2009, two months into his presidency, Obama issued his first signing statement and has since authored at least twenty others. One such signing statement in April 2011 declared Obama's intention not to abide by a section of a bill that defunded several agency "czars."

9. Transparency in the passage of the Affordable Care Act

of transparency in his quest for health care reform. At a January 2008 Democratic candidates' debate, the candidate declared that the process would not include "negotiating behind closed doors, but all parties together and those negotiations on C-SPAN."

During the primary and general election, Obama made several promises

Obama admitted this was a broken promise in an interview with ABC's Diana Sawyer. This broken promise, which C-SPAN was prepared to help the president fulfill, was:

legitimate mistake that I made during the course of the year, and that is that we had to make so many decisions quickly in a very difficult set of circumstances that after awhile, we started worrying more about getting the policy right than getting the process right.

10. Executive Privilege

In 2007, with regard to the Bush administration's dismissal of several Justice Department attorneys, Senator Obama criticized the administration's tendency to:

"ide behind executive privilege every time there's something a little shaky that's taking place. The administration would be best served by coming clean on this. There doesn't seem to be any national security issues involved with the US attorney question. There doesn't seem to be any justification for not offering up some clear plausible rationale for why these US attorneys were targeted when, by all assessments, they were doing an outstanding job. I think the American people deserve to know what was going on there.

On June 20, 2012, President Obama invoked executive privilege for the first time when the House Committee on Oversight and Government Reform was preparing to vote Attorney General Eric Holder in contempt of Congress for his failure to supply subpoenaed documents related to the failed "Fast and Furious" operation that resulted in the death of border agent Brian Terry.