The wife of Sen. Bernie Sanders is under federal investigation for her role in a land deal that went bad, and the Vermont senator has slammed reports of the investigation as "pathetic" and believes his wife to be "the most honest person I know."

Because Sanders hasn't ruled out a presidential run in 2020, any federal investigation has the potential to become disastrous or, at the very least, politically embarrassing. And because the scandal touches on the themes of education costs and six-figure severance packages – two issues that were central to Sanders' populist message – discussing the investigations at all could tarnish his brand as a champion of the little guy.

There are high stakes for some Republican interests as well, as the federal investigation was likely started after the vice chairman of the Vermont Republican Party wrote a letter to the U.S. attorney in Vermont, and that person is rumored to be a potential nominee by President Trump to fill the same U.S. attorney's role he appealed to in the first place.

Here's a walk-through of the background events that have led to this point.

Bernie Sanders met Jane O'Meara in 1981, when Sanders was still the mayor of Burlington, and the two were married in 1988.

In 2004, Mrs. Sanders took over as the president of Burlington College, a small liberal arts college that had a student body that normally floated around 200 students. Prior to that, she had served briefly as the acting president of her alma mater, Goddard College.

A real estate deal initiated during Mrs. Sanders' time at Burlington College is the crux of the problems and resulting investigation.

As the college had hoped to expand its enrollment upwards of 500 or even to 700 students, Sanders brokered a deal in 2010 to add 33 acres to the campus by purchasing a stretch of land along the waterfront of Burlington's Lake Champlain. The property was bought from the Roman Catholic diocese and also included some buildings used by the church.

The deal was financed with $10 million in bonds and loans, according to the Burlington Free Press.

In some ways, the expansion was a "Field of Dreams" experiment – "If you build it, they will come." However, the projected increases in student enrollment didn't materialize, and before long, the college couldn't handle its debt service.

Sanders left as president in 2011 for reasons that weren't disclosed, reportedly taking a $200,000 severance. In 2016, Burlington College went under, specifically citing the debt from the land deal as the major reason for the closure.

Because the FBI has declined to comment for several months now, it's difficult to know what specifics investigators are looking for, but reporting by the local site VTdigger.org shows there may have been problems with pledges some community members made that Burlington College used as collateral in obtaining the financing.

In early May, VTDigger reporter Morgan True and his colleagues tracked down a donor who had pledged a gift to the university that would be bequeathed at the time of the donor's death. The news outlet reported:

Sanders, the wife of U.S. Sen Bernie Sanders, I-Vt., appears to have counted [donor Corinne] Maietta's bequest as a cash gift that was available as collateral to finance the land deal. The 2010 loan agreement says "CBM" pledged $1 million to the school over five years in increments of $150,000, with a final payment of $100,000 in year six.

In an interview, Maietta was incredulous that Burlington College would try to use her bequest to secure a bank loan. "You can't borrow money on the future," she said. "That doesn't exist."

True said Maietta's gift was marked as "confirmed" in the loan document.

"That's probably the most significant pledge that's in question, because it's ... more than a third of the total pledges that were used as collateral, and there's a dispute about whether it was represented accurately in the loan document and whether it was backed by a signed agreement," True told the Washington Examiner.

The senator and his wife have said that the investigations are politically motivated, and it is not disputed that the vice-chairman of the Vermont Republican party, Brady Toensing, likely got the ball rolling when he wrote a letter to the U.S. attorney for Vermont as well as to the Federal Deposit Insurance Corp. in January of 2016 asking that they investigate the loan.

Toensing had deflected those claims by asserting that the investigation was begun under the Obama administration.

The final president of the college, Carol Moore, unloaded on Sanders and the Burlington College board in an op-ed in late August of 2016, after Bernie Sanders was no longer a presidential contender.

She wrote:

BC's fate was set when its former board members hired an inexperienced president and, six years later, approved the imprudent purchase of a $10 million piece of property for campus expansion. Enrollment that year was about 195 and the budget just over $4 million, less than half of this ill-advised investment. What were they thinking? Where was the Finance Committee when these decisions were being made?

At least in Vermont, the Sanders family appears to be weathering the storm.

"I don't know that it's affecting Bernie Sanders' political prospects at this point. His supporters in Burlington tend to think of this as a sideshow," True said.