This strategy has hit British politics like a tornado and has left broadcasters, the opposition, commentators and voters who care about veracity floundering. Mr. Johnson and his ministers have lied fluently and persistently about everything from their fundamental and fake promise to the electorate — that Brexit can be brought to a swift, neat end by him — to its damage to jobs, its impact on Northern Ireland, the ease of new trade deals and the number of new hospitals and nurses the Tories will fund.

It gets even more shameless. The Tories falsely recut a video of an opposition politician. They brazenly rebranded their Twitter account as a fact-checking site during a crucial political debate. They persistently claim that the election had to be called because Parliament had blocked Mr. Johnson’s Brexit deal and voted down his program for government, both of which are false.

Mr. Johnson is not being exposed or embarrassed by his lies because the flood of them is overwhelming, because Britain’s powerful right-wing press is backing him and because he’s dodging any format that could sustain a challenge to him. He has skipped public questioning in favor of carefully constructed photo-ops. He has refused tough interrogations, wriggling out of a slot with the BBC’s most rigorous interviewer.

Mr. Johnson’s team has seized upon a terrifying truth: that the old media, particularly the broadcasters, and the establishment that has decided its rules of operation, are no longer the gatekeepers to communication. Cunning politicians can skip accountability, and British broadcasting’s rules on impartiality and balance, by going straight for the voters’ emotional jugular. In place of public and professional scrutiny there’s Twitter and Facebook, where millions of micro-targeted messages are flooding key voters.

These focused, ferocious evasions of democracy’s conventions and protections appear to be working. The Tories are ahead in the polls and apparently heading for a majority, though the race is tightening and the polls could be wrong. Voters in focus groups parrot Mr. Johnson’s slogans. If the Tories win, they’ll shrug off critics; the demos has approved their tactics.

I dread how a Tory victory would embolden Mr. Johnson and his strategists. Already they are threatening the futures of broadcasters who embarrass them. Already their manifesto promises to look again at the relationships among Parliament, the government and the courts, which is code for: We intend to emasculate anything that constrains us. Given greater power, they will seize more.