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Julian Zelizer: For all that we know, there are still many mysteries about the 2016 election

To find out why we now have President-elect Trump, we should be asking ourselves five main questions, he says

Editor’s Note: Julian Zelizer is a professor of history and public affairs at Princeton University and a New America fellow. He is the author of “Jimmy Carter” and “The Fierce Urgency of Now: Lyndon Johnson, Congress, and the Battle for the Great Society.” He also is the co-host of the podcast “Politics & Polls.” The opinions expressed in this commentary are his own.

(CNN) —  

When historians look back at the 2016 election, there will likely be many big mysteries to solve.

More than many other election in recent history, this heated contest included a number of bizarre game-changing moments that seemed to swing the race in dramatic new directions. And weeks after the election’s surprising outcome, people are still debating what produced the result.

Even as the initial accounts emerge about these turbulent months, we still don’t know the real story behind a number of pivotal moments that led to the election of Donald Trump.

Here are some of them:

Who leaked the ‘Access Hollywood’ tapes and Trump’s tax returns?

There were two moments when Trump’s private life moved front and center in the campaign, posing a serious threat to his candidacy. One was the release of the “Access Hollywood” tapes revealing him making degrading comments about women and suggesting a proclivity to sexual assault, and the other was when the New York Times finally obtained a partial copy of an older tax return showing that he had claimed a tax loss, which helped him avoid paying many millions in taxes on his income.

In both cases the revelations swung the news cycle and forced the Trump campaign into a defensive crouch. They exposed two huge vulnerabilities of his candidacy, his treatment of women and his cheapness and refusal to fulfill obligations. In each case, Trump was able to survive the scandals by shifting attention to other issues and spinning the stories in a way that fit his anti-establishment narrative.

But the questions remain: Who leaked the “Access Hollywood” tapes, and who sent the tax returns to the Times?

Did the Russians coordinate their activities with the Trump campaign?

One of the most troubling allegations to surface during the final months of the campaign was that members of the Trump team were coordinating with officials and hackers in Russia who were trying to sway the election.

There is now an abundance of evidence that Russians engaged in a series of dirty tricks, from hacks into the Democratic National Committee emails that revealed embarrassing information to the distribution of fake news that spread vast amounts of false information to the electorate. Eyebrows were raised when reporters revealed connections between Russians and pro-Russian forces in Eastern Europe, such as advisor Paul Manafort’s consulting work in the region.

When Trump called on Russians to continue hacking in July, he raised more questions about whether he was calling for campaign espionage. “Russia, if you’re listening, I hope you’re able to find the 30,000 emails that are missing. I think you will probably be rewarded mightily by our press,” he said, referring to Hillary Clinton’s messages while she was Secretary of State. Trump later said he was being “sarcastic.”

There had were warnings about efforts to hack voting machines, though no evidence emerged of this happening. The direct connection between Trump and the Russians was not proven and it is a question that will interest scholars as they try to understand how this unfolded.

Over the past week the Russia hacking controversy has intensified. The nation’s intelligence agencies have reached agreement that the Russians hacked the campaign and President Obama has vowed to respond. “We need to take action,” Obama said, “and we will.” There is not a consensus behind the intentions of the hack but it is pretty clear that the intervention happened.

Although President-elect Trump was initially defensive about the news, acting as if it implied he didn’t win legitimately, in recent days there has been some softening of his tone. But he has continued to make a number of very pro-Russian picks, including his possible Secretary of State, in the middle of this major scandal.

Why Did James Comey release his letters?

One of the most damaging moments in the campaign came when Comey announced October 28 that the FBI was looking into emails found on the computer of Huma Abedin, Hillary Clinton’s assistant, that could possibly be related to the State Department email scandal. “Yesterday,” the letter said, “the investigative team briefed me on their recommendation with respect to seeking access to emails that have recently been found in an unrelated case. Because those emails appear to be pertinent to our investigation, I agreed that we should take appropriate steps to obtain and review them.”

The letter brought a new round of scrutiny into the story about whether Clinton had discussed classified material on non-secure servers, a centerpiece of Trump’s allegation that she was “Crooked Hillary.” The news stopped Trump’s sliding poll numbers that had resulted from allegations of sexual assault and renewed concerns about whether there was something bigger to the email story after all – only months after Comey had revealed there was no basis for an indictment.

A week later, just two days before the election, Comey released a second letter saying there was nothing in the emails. But Clinton officials say the letter hurt her by bringing up the scandal again so close to the election.

Why did Comey do this? Why didn’t he or the President say anything about the investigations into the Russia hacks? Some Democrats speculated that there were partisan motivations behind this decision – that Comey, who was a registered Republican (up until July) working in a Democratic administration, was out to get the nominee.

Others argued that Comey’s commitment to being perceived as apolitical and independent had come under attack when he closed the investigation a few months earlier, so he was determined to show that he was not being intimidated by the Obama administration. Still others argued that he felt the obligation to release the information so that voters would not think, after a Clinton victory, that the results had been unfair. We need to know why Comey did what he did.

How much were Trump’s supporters motivated by hate?

The Trump campaign featured an overwhelming barrage of angry and derogatory messages about women, about immigrants and about Muslims. The campaign also brought into the open anti-Semitic rhetoric and reactionary talk about race relations. Yet since the election, as experts sort though the data, there has been some pushback from observers who point out that many Trump supporters did not support him because of these messages.

Rather, the argument goes, they wanted someone who could help the economy, they liked his personality or attitude, they just wanted to keep voting Republican or they didn’t think much of Hillary Clinton. Even CNN analyst Van Jones, who had been especially emotional in attacking Trump for his dangerous vitriol, is now reminding his viewers that there was much more to the Trump vote.

So how much was the hate a driving part of this electoral outcome? This is a very important question, not only to better understand this election but to understand what’s going on in the electorate. It would be a mistake to discount the possibility that many voters were just fine with his rhetoric, and even agreed with what he said. We need to know.

Did voter fraud laws suppress and discourage voting in key states like Wisconsin?

Voting-rights experts like Ari Berman and Michael Waldman of the Brennan Center had been warning for months that all of the voting-fraud measures added to the books in the last few years would discourage voters from turning out.

Based on spurious allegations of massive voting fraud, a number of states responded to the Supreme Court’s evisceration of the Voting Rights Act of 1965 in Shelby V. Holder (2013) by placing more prohibitions and barriers to exercising the right to vote. They also warned that these laws would fall hardest on minority groups who might not have the proper identification or would come to fear just showing up at the voting booth even though they had no reason to do so.

This was the first post-Voting Rights Act election, they reminded us. Trump added to his atmosphere by whipping up his supporters with fears of rigged elections and calling on them to go out in states like Pennsylvania to monitor against fraud.

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Given that Hillary Clinton won the popular vote by 2.5 million votes and that Trump’s victories in key states were extraordinarily narrow, the impact of the laws is important, not simply in terms of the health of our democracy but in terms of the results. Given how narrow Trump’s Electoral College victory was in Wisconsin and Michigan, where such laws are on the books, we need to analyze how they might have depressed the Clinton vote and whether this was part of why she lost.

There are many more questions that will fascinate historians, including some that are not simply about the game-change dynamics of the race. Regardless, it is clear that this was a campaign of great mystery. And for all we know, a lot remains to be uncovered.