For right-leaning and conservative public figures in support of Donald Trump, this has risen to the level of a rallying cry.
I would argue that it probably started not long after the election, but is probably most easily observed in this interview with Sean Hannity last October, emphasis mine:
...[H]ere is the story, this was an excuse by the Democrats and people got carried away. This was a terrible and it's very bad for our country -- during this campaign, forget it. Forget it. This was an excuse that was used by the Democrats.
An excuse for losing an election that frankly they should have won, because winning the Electoral College is so easy for Democrats. They start off with three major states. To win the electoral college for a Democrat, it's almost like a given. That is why people said you cannot get to 270.
(That site has a lot more. I can't link to it all but I highly encourage the curious to peruse it.)
It isn't much of a stretch to presume that this statement was made as a way to appeal to either Trump directly, or to Trump's most staunch Senate supporters. Kavanaugh himself made this process seem directed at him in an overly aggressive political fashion, and made it appear as if he were the one under assault by Democrats and (by extension) Clinton supporters, emphasis mine (and dovetailing into the earlier referenced quote).
This whole two-week effort has been a calculated and orchestrated political hit, fueled with apparent pent-up anger about President Trump and the 2016 election, fear that has been unfairly stoked about my judicial record, revenge on behalf of the Clintons and millions of dollars in money from outside left-wing opposition groups.
From this, I surmise that this is a rallying cry; one which very neatly stokes the emotion-charged events of the 2016 election, and one which galvanizes sides very quickly.