Former Republican Virginia governor Robert McDonnell is on trial in a gifts scandal that all started with an allegation from a chef. The Washington Post's Rosalind Helderman explains the major players in the case and the criminal punishments he might face. (Jeff Simon/The Washington Post)

The federal corruption trial of former Virginia Gov. Robert F. McDonnell and his wife, Maureen, opens Monday. Here are five things we’ll be watching in the courtroom as we look for new revelations about the McDonnells’ relationship with dietary supplement executive Jonnie R. Williams Sr. and for clues to how the case is proceeding.

1.) What’s Jonnie Williams’ story?

He is the prosecution’s star witness, the man who has apparently told authorities that the former governor and his wife agreed to sell his office in exchange for private plane rides, designer clothes, luxury vacations and $120,000 in loans. But Williams has never spoken publicly about the case.

While the broad outlines of Williams’s tale are known, the details are not, and they will make a difference. What, exactly, does Williams claim he said to McDonnell and his wife about the gifts? How does he claim the governor responded?

A manicurist and a model are just two of the witnesses that may be called to testify in the federal corruption trial of former Va. governor Robert F. McDonnell and his wife, Maureen, which commenced on Monday. The Washington Post's Matt Zapotosky reports from Richmond on some of the standout witnesses on the list released by prosecutors and defense attorneys. (Ashleigh Joplin/The Washington Post)

For a conviction, prosecutors will need to show that McDonnell and Williams entered into a quid pro quo agreement in which the former governor agreed to perform “official acts” in exchange for items of personal benefit.

But they don’t need to prove the two men shook hands on an explicit bargain. It’s enough to show that McDonnell generally understood the terms of the arrangement. Will Williams’s testimony persuade jurors that he struck a deal with the governor?

Friends say Williams is brash, boastful and charming, but is he believable?

2.) Can prosecutors persuade jurors this was more than politics as usual?

To get elected, politicians have to ask people for money. In exchange, they sometimes provide campaign donors with access — meetings with the elected official or his staff, invitations to parties, VIP photographs. It may be icky, but it happens all the time. So why is Bob McDonnell on trial?

That’s been a core argument from McDonnell’s legal team in court filings.

To win a conviction, prosecutors will have to persuade jurors — who, if they are like most Americans, will likely approach the case with a deep cynicism about the political process — that what happened between McDonnell and Williams went beyond standard political glad-handing.

For one, they will note that Williams wasn’t just making contributions to McDonnell’s campaigns, something he might have done to advance his own political ideology. He was buying the McDonnell family golf clubs and iPhones and paid to cater the wedding of the governor’s daughter.

They also will have to persuade a jury that the assistance the McDonnells provided Williams went beyond mere access, that the meetings McDonnell set up, that a party he hosted for Williams’s dietary supplement at the governor’s mansion and the conversations the governor had with his staff about Williams’s product — that these things together constituted official acts.

3.) What was Maureen McDonnell up to, and how much did her husband know about it?

One core of McDonnell’s defense has been clear: He’ll say this whole Jonnie Williams thing was his wife’s fault.

His lawyers have repeatedly noted in court papers that many of the most potentially damning accusations in the joint indictment are leveled at the former first lady rather than her husband.

McDonnell, his team has said, was in the dark about many of his wife’s dealings with Williams.

So is McDonnell throwing his wife under the bus? Not necessarily. This argument could protect both the former governor and his wife.

That’s because as an unelected and unpaid first lady, Maureen McDonnell was a private citizen. She wasn’t capable of taking bribes in exchange for selling her own office. Instead, she is charged with working with her husband to sell his office. The idea is that she at times acted essentially as his agent, soliciting items the two of them wanted and promising actions on his behalf.

But the theory could start to fail if a jury believes she was acting on her own, that her husband didn’t know about the gifts she was getting and didn’t know about any promises she was making in exchange.

Expect to hear a lot of awfully personal information about the McDonnells’ marriage as the defense tries to show the couple’s relationship had frayed under the time commitments and pressures of high office.

The prosecution will counter that McDonnell was a willing participant in the relationship with Williams and often acted even without his wife — after all, it was McDonnell who personally negotiated a $70,000 loan from Williams in 2012.

4.) Were the McDonnells financially strapped?

The January indictment includes hints of a possible motive for why the former governor and his wife would risk his promising political future by accepting gifts and money from a character like Williams: Perhaps they were secretly struggling with cash.

According to the indictment, Maureen McDonnell e-mailed one of her husband’s staffers before McDonnell took office to complain that the couple had an “unconscionable amount in credit card debt.”

The issue could form one of the trial’s potentially more intriguing human dramas: the picture of a high level official, living in the governor’s mansion and hobnobbing with wealthy donors all while trying to cover up his own struggles with money.

But for prosecutors, there may be a problem: McDonnell’s lawyers have said the couple’s finances were “fundamentally sound.” If the McDonnells were doing fine, jurors might find it harder to believe he would make an illegal deal with Williams.

5.) Who will testify for — and against — the former governor?

One irony of the case is that the witness list for the prosecution is likely to be filled with people who consider themselves loyal to the governor.

Former staffers, all of the McDonnell’s grown children, the former governor’s sister — all could be called by the government as they try to make their case against him.

Former employees are likely to take the stand, including his chief-of-staff, top political advisor, former legal counsel, director of communications and a number of cabinet secretaries.

So far there has been every indication that McDonnell’s former staffers (not to mention family members) remain loyal and will testify only reluctantly.

But the staffers are also former government employees with their own futures and reputations to protect. If their former boss’s relationship with Williams felt at all fishy to them at the time or if they were asked to take meetings or otherwise work with Williams in ways that felt out of the ordinary, they may feel bound by oath to admit it.

Meanwhile, the McDonnells have asked to call up to 10 witnesses each to testify to their character; the judge has said he is more likely to allow five each. In court filings, McDonnell’s lawyers have argued that proving his good character will be the key to their case. So he will need to choose his witnesses carefully.

Virginia House Speaker William J. Howell (R-Stafford) and Northern Virginia donor and friend Bobbie Kilberg have both confirmed that they have agreed to serve as witnesses, but it is not yet clear if they will make McDonnell’s list.