Readers offer analysis and advice about the Democrats’ plight. Also: An Israeli’s heroism.

Health has become polarized by the Trump administration, which shares an ethos with “The Biggest Loser,” including an obsession with personal responsibility.

Without trust between America and China on A.I., the risks extend far beyond their borders.

Building bigger A.I. isn’t leading to better A.I.

The city embraced new technology without much thought to the consequences — and regretted it.

What comes next?

The conviction of the transitional prime minister in Chad is emblematic of how democracy is eroding across northern Africa.

Curbing Google is an overdue return to the government’s longtime role in encouraging competition among tech companies.

A decade on, Angela Merkel’s immigration disaster has created a right-wing surge.

The left has a birthrate problem. Their pessimism might cost them converts.

Readers respond to a column by David Brooks. Also: Juxtaposing a Nobel Peace Prize and a Department of War.

The legal scholar Kate Shaw discusses Donald Trump’s recent winning streak with the Supreme Court and what it means for the state of the Constitution.

How should his opponents respond?

The legal scholar Kate Shaw discusses Donald Trump’s recent winning streak with the Supreme Court and what it means for the state of the Constitution.

If Democrats gerrymander California, they will lose the moral high ground.

The impact of climate change on the geographic features that demarcate many frontiers is adding to longstanding beefs over borders.

Besides, addicted people are not the only ones affected by their behavior.

With support, returnees’ skills and resilience can fuel economic growth back home.

The U.S. and China must agree on a trust architecture for A.I., or rogue entities will destabilize the two superpowers long before they fight a war.

Is our vaunted system really safe from the shameless likes of Trump?

Agency leaders sound the alarm.

Together, we can help ensure that beautiful birds continue to grace our skies.

Ending cash bail works. Trump wants to bring it back everywhere anyway.

Even if Mr. Mamdani is as awful as his opponents insist, campaigning against an opponent’s flaws works only if you don’t seem even worse.

The new, higher premium placed on college application essays that focus on racially traumatic experiences produces numerous undesirable consequences.

Why the labor movement needs to act like its future is under grave threat.

For President Luiz Inácio Lula da Silva of Brazil, the stakes ahead of next year’s election could not be higher.

Readers respond to an essay by a conservative mother on the importance of Medicaid to the care of her disabled son.

The ban indicates that Israel’s leaders are deliberately trying to conceal the war’s full horror.