One of those cases did go public earlier in December, and it involved Republican Congressman Blake Farenthold. Farenthold has responded by saying he won't run for re-election in 2018, but the pressure for him to resign now is high. He won't be the last member of Congress to deal with pressure like that in the coming months.

Sources say that pressure is leading to a widespread fear factor on Capitol Hill. Dozens of staffers have told CNBC they're starting to make contingency plans in case their elected bosses get ensnared in the next sexual misconduct allegation to go public.

They have reason to be afraid, not least because these secret settlements have all been handled by the Congressional Office of Compliance, an entity Democratic Rep. Jackie Speier has accused of being an "enabler of sexual harassment." Speier and other members of both parties are currently trying to unseal the office's secret deals. That increases the odds that some or even most of these cases will become public.

So far, the focus on the effects of the harassment scandals has been squarely on House. But any member of the House or Senate serving for more than a year at any time since 1997 could be named in one of those 264 sealed settlements.

Here's where the math and the probabilities get really interesting: A whopping 31 members of the 100 member Senate have been serving in one part of Congress for every single year since 1997. Again, in a U.S. Senate almost evenly split down the middle, 31 senators is a lot of potential perpetrators.

The party breakdown among those 31 senators is 18 Republicans and 13 in the Democrat caucus. They include top leaders from both parties and key senators from swing states that could easily swing to the other party if the incumbent were forced to resign. Most importantly, 8 of them, six Democrats and two Republicans, are running for re-election in 2018. Three of those elections are currently in the "toss up" category according to the election site, 270towin.com.

It's important to pause here and make it clear that there is no solid evidence any of those 31 senators are involved in those sealed misconduct cases. But if they are, the swift and unforgiving nature of these scandals is abundantly clear from what happened to Conyers, Franken and others in just the last two months.