WASHINGTON — For­mer Pres­i­dent Barack Oba­ma paint­ed a unspar­ing por­trait of Amer­i­can democ­ra­cy on the brink if Pres­i­dent Don­ald Trump wins in Novem­ber, warn­ing in a scathing, and at times emo­tion­al, address Wednes­day that his suc­ces­sor is both unfit for office and apa­thet­ic about the nation’s found­ing principles.

“This admin­is­tra­tion has shown it will tear our democ­ra­cy down if that’s what it takes to win,” Oba­ma said in strik­ing­ly blunt remarks on the third night of the Demo­c­ra­t­ic con­ven­tion. He spoke from Philadel­phia, where the Unit­ed States Con­sti­tu­tion was draft­ed and signed.

Obama’s address amount­ed to one of the most sweep­ing con­dem­na­tions ever of a sit­ting pres­i­dent by one of his pre­de­ces­sors. It was aimed square­ly at jolt­ing Democ­rats, as well as Repub­li­cans who are skep­ti­cal of Trump, ahead of the Novem­ber elec­tion, cast­ing the con­test not sim­ply as a choice between two politi­cians or two par­ties, but as a test of the endurance of Amer­i­can principles.

Through much of Trump’s pres­i­den­cy, Oba­ma has been restrained in his pub­lic com­ments, hew­ing to the tra­di­tion of for­mer Oval Office occu­pants giv­ing space to the cur­rent com­man­der in chief. Yet he has become more point­ed in his crit­i­cism in recent months, and his remarks Wednes­day revealed the full extent of both his per­son­al dis­re­gard for the cur­rent pres­i­dent and his belief that Trump presents an exis­ten­tial threat to democ­ra­cy in the Unit­ed States.

Oba­ma said he had ini­tial­ly held out hope that Trump would grow into the job of pres­i­dent — but he has now con­clud­ed that Trump not only hasn’t, he sim­ply can’t. Instead, he said Trump has focused on using the pres­i­den­cy to ben­e­fit his friends and fam­i­ly and turned the nation’s most pow­er­ful office into “one more real­i­ty show that he can use to get the atten­tion he craves.”

The for­mer president’s address also amount­ed to a call to action to a weary and anx­ious nation, par­tic­u­lar­ly younger Amer­i­cans frus­trat­ed with a gov­ern­ment that may often appear out of touch with their inter­ests. Democ­rats see Oba­ma as a bridge to those vot­ers in the 2020 race, some­one who can speak both to Biden’s char­ac­ter and to the urgency of pro­gres­sives push­ing for more sweep­ing change to the nation’s eco­nom­ic and domes­tic policies.

“I am also ask­ing you to believe in your own abil­i­ty — to embrace your own respon­si­bil­i­ty as cit­i­zens — to make sure that the basic tenets of our democ­ra­cy endure,” Oba­ma said.

Yet there’s an inher­ent ten­sion in Obama’s role as one of the most pow­er­ful and impor­tant sur­ro­gates for Biden. Obama’s own polit­i­cal rise was fueled by the pow­er of bar­ri­er-break­ing, gen­er­a­tional change, and he’s encour­aged “new blood” in pol­i­tics. More recent­ly, Oba­ma drew atten­tion dur­ing the 2020 Demo­c­ra­t­ic pri­ma­ry when he said many of the world’s prob­lems have been due to “old peo­ple, usu­al­ly old men, not get­ting out of the way.”

With the gen­er­al elec­tion now in full swing, Oba­ma con­fi­dants say that while the for­mer president’s sup­port for Biden is unequiv­o­cal, he does wor­ry about enthu­si­asm among younger vot­ers, par­tic­u­lar­ly younger vot­ers of col­or. He’s well aware that one of the rea­sons Trump cur­rent­ly occu­pies the Oval Office is that those vot­ers did not show up in the same large num­bers in 2016 for Hillary Clin­ton as they did when he was on the ballot.

Speak­ing at a news con­fer­ence Wednes­day, Trump shrugged off Obama’s crit­i­cism, say­ing that if the for­mer admin­is­tra­tion had done a good job, “I wouldn’t be here.”

Trump added, “And prob­a­bly if they did a good job, I wouldn’t have even run.”

Oba­ma spoke two nights after his wife, for­mer first lady Michelle Oba­ma, head­lined the open­ing night of the con­ven­tion. The fact that the Oba­mas are head­lin­ers on two of the four nights of the Demo­c­ra­t­ic cel­e­bra­tion speaks to the cru­cial role they have in help­ing Biden try to reassem­ble the coali­tion that pro­pelled them into the White House — and the chal­lenge the Demo­c­ra­t­ic Par­ty has in build­ing a new bench of oth­er lead­ers who can do the same.

“When you think about folks who have the capac­i­ty to real­ly uni­fy us, there are only a few peo­ple,” said Yvette Simp­son, chief exec­u­tive of Democ­ra­cy for Amer­i­ca, a pro­gres­sive polit­i­cal action com­mit­tee. “Cer­tain­ly Barack Oba­ma and Michelle Oba­ma are among them.”

Indeed, the for­mer pres­i­dent has envi­able pop­u­lar­i­ty, both among Democ­rats and all Amer­i­cans. A Fox News poll con­duct­ed in May found 93% of Democ­rats had a favor­able opin­ion of Oba­ma, as did 63% of all reg­is­tered voters.

Despite that strong sup­port, there has been some rethink­ing of Obama’s lega­cy among some of his party’s most lib­er­al activists, who argue he didn’t go far enough in over­haul­ing the nation’s health care sys­tem and gave too much away to Repub­li­cans in fis­cal nego­ti­a­tions. Oba­ma him­self has acknowl­edged there was more he want­ed to do, but argued he was ham­strung by the real­i­ties of a Repub­li­can-con­trolled House, and even­tu­al­ly Sen­ate, for much of his tenure.

But some of Obama’s more recent com­ments have ener­gized lib­er­als, who see signs of him embrac­ing some of the tac­tics of his party’s activist wing. Pro­gres­sives cheered in par­tic­u­lar when Oba­ma called for elim­i­nat­ing the Sen­ate fil­i­buster rules requir­ing 60 votes on major pieces of leg­is­la­tion, call­ing it a “Jim Crow rel­ic” that is hold­ing up rewrit­ing vot­ing rights laws. His sur­prise com­ments came dur­ing his eulo­gy at the funer­al of the late civ­il rights leader and Geor­gia Rep. John Lewis.

“That’s the guy we remem­ber from the elec­tion of 2008,” Simp­son said of Obama’s remarks at Lewis’ funer­al. “It encour­aged me that he might be the guy that pulls Joe Biden along a lit­tle bit.”