PHILADELPHIA ― Vice President Joe Biden offered a counterargument to the premise of Republican presidential nominee Donald Trump’s case for the White House with an emphatic declaration that the America is great already ― and that a Trump presidency would jeopardize that.

“We’ve had candidates before attempting to get elected by appealing to our fears, but they’ve never succeeded because we do not scare easily. We never bow, we never bend, we never break, when confronted with crisis. No, we endure! We overcome and we always, always, always move forward,” Biden said amid cries of “U.S.A.!” from the Democratic National Convention crowd Wednesday.

Biden enthused about American workers, the economy and the military; blasted Trump’s ignorance of domestic and world affairs; and issued grave warnings about the consequences of the real-estate billionaire’s vision for the world.

“This is a complicated and uncertain world we live in. The threats are too great, the times are too uncertain to elect Donald Trump president of the United States,” Biden said. “No major party nominee in the history of the nation has ever known less or been less prepared to deal with our national security.”

Mike Segar/Reuters U.S. Vice President Joe Biden addresses the Democratic National Convention in Philadelphia on Wednesday.

Biden’s address to the convention was founded on a two-part argument that Democrats are making to persuade voters ― however skeptical they may be of Democratic nominee Hillary Clinton ― that Trump’s negative outlook on America is misplaced and that his strongman approach to problems at home and abroad will threaten the foundation of the nation’s strengths.

Trump’s strident views about national security, terrorism, America’s relationship with allied nations and other issues would lead to catastrophe if he were in the White House, Biden said.

“We cannot elect a man who exploits our fears of ISIS and other terrorists, who has no plan whatsoever to make us safer, a man who embraces the tactics of our enemies, torture, religious intolerance,” Biden said.

“It betrays our values. It alienates those who we need in the fight against ISIS. Donald Trump, with all his rhetoric, would literally make us less safe,” Biden said. “We cannot elect a man who belittles our closest allies while embracing dictators like Vladimir Putin ― I mean it ― a man who seeks to sow division in America for his own gain and disorder around the world. A man who confuses bluster with strength.”

The vice president also endeavored to use Trump’s reality TV stardom against him.

“His cynicism is unbounded. His lack of empathy and compassion can be summed up in the phrase I suspect he is most proud of making famous: ‘You’re fired,’” Biden said. “Think about everything you learned as a child. No matter where you were raised, how can there be pleasure in saying, ‘You’re fired’? He is trying to tell us he cares about the middle class? Give me a break. That’s a bunch of malarkey.”