I'm leaning towards it being a political tool of harassment by conservatives. They couldn't stand the fact that Bill Clinton was actually a good President and they were terrified by the notion that Hillary was a danger to gain political influence following Bill's Presidency. They have trumped on charges and spent hundreds of millions of dollars trying to find something to prosecute her for and have come up with nothing. There is no one in this nation who has been more closely scrutinized than Hillary Clinton, yet the GOP has found nothing they could punish her for.
But that's okay to them because they learned along the way that the accusation is almost as good. Just come up with something, make the accusation, see if it gets traction on Limbaugh, Hannity, Breitbart, etc. If it does, roll with it. If not, think of something else. But whatever the case, just keep pumping out the accusations.
There is no pursuit for the truth by the GOP. Bush/Cheney deleted millions of emails. MILLIONS. Where was the truth-seeking GOP then? Why were more hearings held on Benghazi and more money spent on those hearings than 9/11? Why the outrage over 4 dead when more than 60 died in similar situations under Bush/Cheney? Why not a single investigation of that? Where was the willingness to hold Bush/Cheney responsible for 9/11, where 3,000 people died? The lies about WMD's and the failure to plan for the aftermath of the Iraq war? The loss of $12 billion in cash that disappeared on a slow boat to Iraq?
The fact is that no matter what Hillary has done--and I'm talking about actual things, not made up Hillary and Bill hire assassins type of nonsense---it can't even begin to approach just one of the outrages that happened from 2000-20008. If we can tolerate that, then Hillary is an angel of pure lightness and good.