There are many differences between the 2012 election cycle and 2008. For President Obama's reelection team, adjusting to the contrasts between running for a first term and asking voters to sign off on a second one has been a challenging task.

In a new eBook out this week titled "Obama's Last Stand," Politico's Glenn Thrush takes a closer look at some of the key moments that have shaped the president's reelection bid so far. Here are some highlights:

* Obama's natural competitive streak was stoked by Mitt Romney: Obama, known by those close to him as a competitive person, was intensely fired up to face Romney and approached the matchup differently from the way he had against other Republicans in the past:

One factor made the grind bearable and at times even fun for Obama: he began campaign preparations feeling neutral about Romney, but, like the former governor's GOP opponents in 2008 and 2012, he quickly developed a genuine disdain for the man. That scorn stoked Obama's competitive fire, got his head in the game, which came as a relief to some Obama aides who had seen his interest flag when he didn't feel motivated to crush the opposition. Obama, a person close to him told me, didn't even feel this strongly about conservative, combative House Majority Leader Eric Cantor, the Hill Republican he disliked the most. At least Cantor stood for something, he'd say. When he talked about Romney, aides picked up a level of anger he never had for Clinton or McCain, even after Sarah Palin was picked as his running mate.

* An internal debate over outside money: There is a major disparity between the financial heft of Republican-aligned outside groups working to defeat Obama, and Democratic groups, which have struggled to keep pace. At first, Obama and top adviser David Axelrod were reluctant to adapt to the post-Citizens United campaign finance landscape by embracing third-party groups, while others in the president's inner circle disagreed. The reality of the situation would later set in, and by early 2012 the president was encouraging donations to a super PAC supporting him. But by then, GOP groups had already gotten a major head start:

When pragmatists like Rahm Emanuel and Jim Messina made the case that Obama needed to tap high-octane talent to create an Obama-allied super PAC to compete with Romney's Restore Our Future, he waved them off. People familiar with the early planning told me that one of the names thrown around to possibly head the effort was Penny Pritzker, Obama's billionaire friend from Chicago, whose influence and connections had helped him compete in a 2008 environment otherwise dominated by Clinton allies. The appeal went nowhere. Obama had no time for super PACs, a political weapon that was to pose a mortal threat to him a year later.

"Stop talking to me about this ... I'm not going there," he told one exasperated adviser around that time.

* Positive/negative balance: Over the summer, Bill Clinton loyalists, concerned about the emerging negative tone of the campaign, had been urging (both privately and publicly) the Obama team to focus on articulating a vision for a second term containing easy-to-grasp policy proposals:

By late July 2012, Obama was telling a group of high-dollar donors at a fund-raiser in Manhattan that he would, in fact, start talking about "the specific agenda that I intend to pursue in the second term" around the time of the convention. Just like Bill Clinton.

But he also hit the history books again to defend his negative campaigning. "I think you're seeing a lot of negative ads and a lot of contrast ads ... [W]hen people start saying how terrible it is, I just have to remind them to take a look at what Jefferson and Adams had to say about each other" in the campaign of 1796. "... [D]emocracy has always been pretty rough and messy."

* Anger at Rick Santorum: When an earthquake hit central Mexico in late March while the president's oldest daughter, Malia Obama, was there on a spring break trip, Santorum said, "the president's actions should reflect what his administration is saying. If the administration is saying that it's not safe to have people down there, then just because you can send 25 Secret Service agents doesn't mean you should do it." Obama was not pleased:

When Obama got wind of Santorum's remarks, he exploded -- and ordered someone on his staff to reach out to Santorum's campaign. This was a rare case in which Obama actually lost his composure, an insider told me, and it seemed as if all the pent-up tensions of the campaign were released in an instant by what always pushed his buttons -- an attack on his family.

John Brabender, Santorum's right-hand man, got a call from a polite but clearly agitated Jim Messina.

"It was made clear to me that the president was very, very upset about this and wanted to get the message to the senator that families were out of bounds," Brabender told me.

* 'Why poke Kennedy?': Obama's communications team, fearing that Supreme Court Justice Anthony Kennedy (often a swing vote on the high court) could move toward voting down the president's signature health care law if he was constantly reading that the administration considered an overturn likely, played their cards close to the vest:

In fact, Obama's communications shop was so nervous about the situation that it long denied making any contingency plans for the law being overturned -- which proved to be untrue. The fear: the perceived swing voter, Justice Anthony Kennedy, was rumored to read blogs online and might be swayed to vote the law down if he heard that the administration already considered an overturn likely, according to a person close to the situation. "Why poke Kennedy? What's the upside?"

* Tensions with Democratic National Committee Chair Debbie Wasserman Schultz: The relationship between Chicago and Wasserman Schultz, the congresswoman from Florida, was uneasy from the start. Some on the Obama team felt she was too partisan in her tone when she did the Sunday shows. Pollster David Binder's company was commissioned by the Obama campaign to rank the effectiveness of Obama surrogates, and the results were not encouraging for Wasserman Schultz:

The results, which were made available to me, placed Robert Gibbs at the top.

Cutter was second (a later version of the poll placed Jen Psaki, who was soon to return to the fold as Obama's traveling press secretary, third).

Axelrod did pretty well. Plouffe and Press Secretary Jay Carney, not so much.

Wasserman Schultz ranked dead last.