WASHINGTON—There was a moment during his Democratic National Convention speech on Wednesday night when former President Barack Obama appeared on the edge of tears. Evoking American ancestors persecuted because of their race, religion or nationality, he said they had every reason to give up on democracy but did not.

华盛顿——在周三晚上的民主党全国代表大会演讲中，前总统贝拉克·奥巴马(Barack Obama)一度近乎落泪。他提起因种族、宗教或国籍而受到迫害的美国祖先，他说他们本来有充分的理由放弃民主，但他们没有。

In his telling, that is what is at stake at this hinge point in history, nothing less than the future of democracy, and he seemed emotional in a way that the famously stoic former president rarely allows himself to be in public. He talked of “dark times” and “hardship and injustice” and “the meanness and the lies and crazy conspiracy theories.” He declared that this year’s election will determine whether America lives up to its promise.

在他的叙述中，这就是眼下历史关键时刻中利害攸关的大事，民主的未来岌岌可危，他似乎情绪激动，而这位以沉稳著称的前总统很少允许自己在公众面前表现出这一面。他谈到“黑暗时代”、“苦难和不公”、“卑鄙、谎言和疯狂的阴谋论”。他宣称，今年的选举将决定美国能否兑现自己的承诺。

His excoriation of his successor was withering. The incumbent president, he charged, is lazy, uncaring and interested only in drawing attention to himself. President Trump, Mr. Obama said, acts as if he is “above the law,” uses his office “to enrich” himself and his allies, exploits the military “as political props” to be deployed against peaceful protesters, demonizes his opponents and the free press, and disregards science during a deadly pandemic in favor of “just making stuff up.” What’s more, he added, Mr. Trump is trying to suppress the vote to stay in office.

他对他的继任者的批评极其尖刻。他指责现任总统懒惰、冷漠，只想引起人们对自己的关注。奥巴马说，特朗普总统的行为仿佛他“凌驾于法律之上”，使用他的职权为自己和盟友“谋财”，把军队当成对付和平抗议者的“政治道具”，妖魔化对手和新闻自由，在致命的大流行期间无视科学，转而去“凭空捏造”。他还说，更重要的是，特朗普试图压制选票，以便让自己连任。

The 19-minute address, delivered in front of an exhibit titled “Writing the Constitution” at the Museum of the American Revolution in Philadelphia, reflected a long journey from the hope and change of 2008 when Mr. Obama sailed into the White House on a fundamentally optimistic message that whatever the country’s problems, they could be solved by coming together. Twelve years later, he did not seem quite so certain. With Mr. Trump in the White House, Mr. Obama sounded more worried than perhaps at any point in his public life.

这场19分钟的讲话是在费城的美国革命博物馆(Museum of the American Revolution)一个名叫“书写宪法”的展览上发表的，反思了一段始于2008年的希望与变革的漫长历程，当时的奥巴马携带着一个根本上乐观的讯息入主白宫：无论这个国家有什么问题，只要团结起来就能解决。12年后，他似乎不那么肯定了。特朗普入主白宫后，奥巴马似乎比他在公众生活中的任何时候都更加忧心忡忡。