The former vice president is shedding a significant percentage of the vote in the low-profile primaries held during the last two months.
Democrats have never nominated a westerner for their presidential or VP slots across the 42 cycles since the first western state voted in a presidential election.
Only three other governors have made more than one appointment to the chamber during the last 64 years.
Democrats and Republicans in 18 states have now set or tied their longest gubernatorial winning streak in party history.
Of the nearly 200 appointments made to the U.S. Senate since the ratification of the 17th Amendment, just five had previously served in the legislative body.
Only one region of the country is regularly seeing both parties win U.S. Senate seats in the vast majority of its states.
John Perdue of West Virginia joins a half-dozen other officeholders who are currently surrounded by state executive officials from the opposing political party.
The progressive senator would be the first major party White House hopeful from the Beaver State in the modern primary era.
Jerry Brown is poised to end up #3 on the all-time list of statehood gubernatorial service.
If a handful of toss-up races all end up in the Democratic column, the party will have its strongest showing in races for governor since its formation nearly 190 years ago.