By dropping his reelection bid, President Biden is reversing more than a century of democratizing the choice of presidential nominees via primaries. That power now shifts back to party bosses from the people, as insiders can swap out any candidate who’s losing and call in a ringer.

“I believe,” Mr. Biden wrote in a letter to the nation on Sunday, “it is in the best interest of my party and the country for me to stand down.” It’s a nit worth picking that he put “party” before “country,” reversing President Hayes’s maxim, “He serves his party best who serves his country best.”

Last week, Mr. Biden told NBC News that he’d “listen to” the 14 million people who voted for him in the primaries and reject calls to ignore them. On Saturday in the Sun, the headline of my column asked, “Is Disenfranchising Millions of Biden Primary Voters ‘What Democracy Looks Like’?”

Now we have our answer: Those ballots are voided. After this, why vote, campaign, or donate money to a primary candidate if your choice might just be cast aside? At least Mr. Biden endorsed Vice President Harris, a candidate whom voters expected might be called upon to replace him.

“You can fool all of the people some of the time,” a quote misattributed to President Lincoln holds, “you can fool some of the people all of the time, but you can’t fool all the people all the time.”

Democrats backing Mr. Biden have failed to fool enough people for a long enough time; so, enter a ringer on a glide path to the top of the ticket. Ms. Harris said in her statement that her “intention is to earn and win this nomination.”

It’s the power brokers — along with the delegates — at the Democratic convention, not voters of the several states, whose support she will have to chase. What might she or other candidates have to promise to win their backing?

Ms. Harris may be able to spend cash donated to the Biden-Harris organization and avoid a fight in states like Wisconsin over putting a new name on ballots. Citizens who support President Trump, however, have had their participation in democracy rendered a farce.

The efforts Trump supporters have made thus far to defeat Mr. Biden in November have been rendered moot. Trump’s triumph in the debate and the RNC’s efforts to offer a contrast with another four years of the incumbent at the helm are likewise for naught.

Since there’s a limit to what citizens can donate to presidential candidates, Trump can’t go back to donors who have given the maximum. Every dollar spent and effort made to beat Mr. Biden in November is wasted now that he invoked the Mercy Rule, quitting because his opponent was running up the score.

Trump — whose opposition research and campaign ads are now largely useless — can’t yet shift to a new opponent. Democrats, meanwhile, can take free punches at him for a full month until their convention concludes. The GOP suffers because their primary process was transparent, not a throwback to the 1800s.

“We are forced to spend time and money on fighting” Mr. Biden, Trump posted on Truth Social. “Now we have to start all over again. Shouldn’t the Republican Party be reimbursed for fraud in that everybody around Joe, including his doctors and the Fake News Media, knew he was not capable of running for, or being, president?”

We now sail into uncharted waters, although the Constitution does not set the way candidates are selected. First, conventions of state delegates chose Electoral College electors. In 1804, as political parties formed against President Washington’s wishes, Congressional caucuses laid out the tickets.

Voters started demanding a say via primaries in the early 20th century, but bosses kept the real power. In 1920, a commentator for the United Press, Raymond Clapper, coined the phrase “smoke-filled room” to describe where Republicans chose President Harding hidden from the public eye.

The devolution of power to the people marched on until the primary system was settled after World War II. In 1952, another unpopular Democratic incumbent, President Truman, lost New Hampshire’s primary by ten points. The bosses could no longer save him; he dropped his reelection bid.

Mr. Biden might have followed that same path, heeding the vox populi as expressed at the ballot box. Instead, his backers iced out challengers like the now-independent candidate, Robert F. Kennedy, Jr., in hopes of concealing the president’s weaknesses until after Election Day.

The strategy was to portray Mr. Biden as a competent statesman. Questions about his faculties were dismissed as “ageism” and “cheapfakes.” Just two weeks ago, the “All In” podcast compiled a montage of “100 spokespeople and proxies” calling Mr. Biden “sharp as a tack.”

Mr. Biden had a childhood stutter, his supporters told America, that had reemerged after a six-decade absence. After the debate, a string of different excuses flowed out of the White House: He was overprepared, suffering from a cold, jetlagged, Trump threw him off his game.

None of this spin persuaded the public; so top Democrats wish to turn their deception into a positive and render the debate result moot. No apology. Since their first scheme to hold onto power failed, they’ll just move on to the next.

Primaries and presidential debates are meant to help voters decide whom they want for president. If party bosses don’t like the verdict that the citizens render, they ought to endure the consequences like all past candidates. Hayes went to sleep on election night believing he’d lost, content that he’d done his best.

The American people accept that candidates are portrayed in their best light and deny unfavorable truths. What they may not forgive is power brokers in modern, vape-filled rooms throwing our democracy into chaos — all because some choose to put party before country, and decide fooling the public with a ringer is easier than making an honest pitch for votes.