There’s an idiom in contemporary politics that goes, approximately, like this: Republicans wake up angry; Democrats wake up sad.

It would seem an inescapable truism, particularly given the rancor that freights this presidential campaign. While it will go largely unnoticed, Mike Pence did something extraordinary Sunday: He promised the nation that his party would peacefully accept the results of the election.

Think about that. Simply as principle, Democracy relies on an assumption that those involved understand the rules of engagement. Rules that weren’t in question say, during the presidential primaries, which were similarly rife with vitriol.

But in watching Pence, I realized that some Republicans must be waking up sad, too.  They also see where this path inevitably leads: To self-cannibalization.

Consider: In 2009, the Tea Party was borne of Republican worry that a newly-elected Barack Obama would usher a Caligula-like era Washington, reeking of liberalism and federal handouts. The party concocted a 10-point Contract from America (not “with,” interestingly). It called for, among other things, that Obamacare be repealed and that all new laws “identify the specific provision of the Constitution that gives Congress” authority to pass new laws.

Alas, the Supreme Court nixed the first provision and voters the second. In response to the non-response, the GOP drifted further right and began to consider Karl Rove’s parting advice to colleagues: expand the base by including more outliers — voters who would normally drift toward fringe candidates.

Thus the birth of Sarah Palin, the least-qualified professional since Marlon Brando whimsically hired a NYC cab driver as his agent (true story).

And now Trump, who makes Palin look MENSA cerebral. Trump has already put the GOP on notice that they will pay just as dearly as Democrats for angering him. Paul Ryan — a founding father of the Tea Party — has been particularly pilloried for non-neo-support. His political career (let alone his hold as House Speaker) is as clear as puddle water.

The pit bull has turned on its dog-fighting owner. Unshackled, if you will.

But Pence’s jaw-dropper followed another: Michelle Obama’s speech days earlier concerning the state of politics, specifically the NC-17 turn it’s taken. While she has traditionally eschewed stumping (she was opposed to her husband’s decision to run for president in 2008), she may have struck an apolitical nerve. One that prompts political action.

There’s a reason the crowd erupted at “enough is enough.”

That’s the tricky thing about energizing bases. You never know their mood when they finally wake up.