In America, we do not have to prove our innocence in court.

In another brilliant scoop, Post writers Rosalind S. Helderman, Carol D. Leonnig and Sari Horwitz revealed last month that the top federal prosecutors in Virginia wanted to indict Gov. Bob McDonnell and first lady Maureen McDonnell on corruption charges stemming from roughly $165,000 in gifts and loans they received from former Star Scientific CEO Jonnie R. Williams Sr.

Taking such an action against a sitting governor requires agreement from superiors at the Justice Department in Washington. But what would normally be a routine sign-off has been inexplicably delayed. The fact that these secretive internal deliberations are now front-page news is just another extraordinary chapter in what’s been an unprecedented, headline-grabbing, election-year federal investigation.

The probe already neutralized what should have been the GOP’s best campaign asset in the governor’s race — McDonnell — and led to the most damaging mistake of the campaign: Ken Cuccinelli’s decision, reversed too late, not to pay back his own gifts from Williams.

What comes next? Using the Socratic method, we can reach Socrates’s conclusion.

Question one:

Did federal investigators have sufficient justification to launch their probe? Absolutely. McDonnell himself has condemned his own terrible judgment in accepting Williams’s gifts.  Even though the governor has repeatedly said he neither broke, nor intended to break, any law, an investigation was still warranted.

Question two:

What has Williams said to federal investigators? Has he suggested to them that the governor knew, or should have known, that the gifts and loans were part of some quid pro quo? McDonnell maintains that Williams claimed to be acting solely as a friend, giving no reasonable cause for him to believe that the 58-year-old Henrico resident expected anything in return for his generosity.

Williams’s background is not widely known, even today, in Virginia. But he has been on the federal government’s radar since the 1980s, according to extensive reporting on his business ventures that appeared in the Boston Globe at the time.  And a 1981 story in the Fredericksburg Free Lance-Star describes Williams as a young “super salesman” and owner of an optician shop who suddenly “departed for parts unknown leaving in his wake a host of debts and countless pairs of unclaimed eyeglasses.”

Prior to the McDonnell probe, Star Scientific faced a federal investigation that was potentially financially ruinous. This securities probe has seemingly stopped.

Our research confirms the observation, made in a Post report, that the “key question for prosecutors is who is most believable about the interactions between the governor and Williams.”

Question three:

Courthouse folklore says that any competent prosecutor can get a grand jury to indict a ham sandwich. But could it reasonably be expected for a Virginia jury to convict a governor based on Williams’s word?  It doesn’t take Oliver Wendell Holmes to figure out that the federal investigation may be colliding with legitimate concerns about a lack of solid evidence. 

Question four:

It may come down to the question of who is the real Jonnie Williams.

Is he the “genius” with “an uncanny ability to see a central path to a solution that other highly trained people have missed,” as a former director of one of Williams’s companies put it”?  Or is he the man who sought to revolutionize the cigarette business by producing “safer” tobacco using a store-bought microwave?

We applaud federal prosecutors for being diligent. They surely fear partisan inferences should a Democratic administration drop the investigation now that the November election has passed. But going to trial based upon testimony from Williams and without the proverbial “smoking gun” would offer little hope of justice.

By logical deduction, Socrates would conclude that it’s time for the federal prosecution to end. He would rely on Virginians to seek to appropriately punish the McDonnells under any applicable state law.

Norman Leahy is an editor of the conservative Web site and producer of the political radio show “The Score.” Paul Goldman is a former chairman of the Democratic Party of Virginia. They are blogging together on All Opinions Are Local during Virginia’s 2014 General Assembly session.