James Comey. Eric Thayer/Getty Images James Comey, the ousted FBI director, testifies before the Senate Intelligence Committee on Thursday in what is certain to be one of the most-watched political events in recent history.

Comey preempted his hearing by authorizing the release of his opening remarks for testimony on Wednesday, giving reporters and political observers time to comb through what the former FBI director plans to say about his private communications with President Donald Trump.

Before Trump fired him in early May, Comey oversaw the FBI's investigation into whether the Trump campaign colluded with Russian officials to interfere in last year's presidential election.

Now that we know what Comey plans to say before the committee in his opening remarks, here's what to watch for.

1. Will Comey answer questions related to whether Trump obstructed justice?

Comey was careful in his written testimony not to make any assertions about whether the president obstructed justice or attempted to obstruct justice in his conversations with the FBI director, outlining what he said the facts of those conversations were. But leading senators on the panel are likely to ask Comey about whether he believes Trump's actions constitute obstruction of justice, the same charge that eventually led President Richard Nixon to resign during the Watergate scandal.

2. Will Comey confirm Trump's account that the FBI director assured the president on three occasions that he was not under investigation?

In his written testimony, Comey said he told Trump on three occasions that he was not the subject of a counterintelligence investigation. But according to Comey's written testimony, Trump became upset that Comey would not confirm so publicly, which Comey said could create a problem if that status were to change.

Senate Intelligence Committee members are likely to ask Comey about those instances. If Comey says the president was correct in that characterization, Trump's supporters both on Capitol Hill and elsewhere will zero in on that as evidence that Trump was in the right.

3. Why didn't Comey take this information to top Justice Department officials?

Some have questioned why Comey did not tell his superiors about his concerns about his conversations with Trump. Comey gave details to senior FBI officials, but he apparently did not tell top Justice Department leaders, such as Attorney General Jeff Sessions, the nitty gritty about what had unnerved him in those conversations. If Comey believed Trump's actions were extremely concerning, senators will ask why he didn't raise those concerns with the top officials in his department.

4. How much does he expand on his testimony?

Comey's written testimony confirms the news accounts that revealed these bombshell claims in the immediate aftermath of his firing, but it did not provide much additional information that had not already crept into the public realm. While Comey will most likely be grilled for hours, how much will he expand on, and how much new information will he provide?