— Several Democratic lawmakers have intensified calls to invoke the 25th Amendment to remove President Donald J. Trump from office, citing his recent efforts to acquire Greenland as evidence of unfitness to lead. The push follows reports linking Mr. Trump’s renewed interest in the Danish territory to frustration over being overlooked for the Nobel Peace Prize.

Senator Ed Markey of Massachusetts led the charge on Jan. 20, posting on social media that Mr. Trump’s statements “show he is unfit for office and could put American safety at risk.” Mr. Markey urged Vice President JD Vance and the cabinet to act under Section 4 of the 25th Amendment, which allows for the temporary transfer of power if the president is deemed unable to discharge his duties. He referenced a leaked text message from Mr. Trump to Norwegian Prime Minister Jonas Gahr Støre, in which the president reportedly stated he no longer felt obligated to prioritize peace after not receiving the Nobel Prize, tying it to U.S. interests in Greenland.

Representative Sydney Kamlager-Dove of California echoed the sentiment, posting on X that “Donald Trump is unfit to lead and clearly out of control. Invoke the 25th Amendment.” Representative Yassamin Ansari of Arizona went further, labeling Mr. Trump “mentally ill” in a statement tied to the same reports. Other Democrats, including Representative Eric Swalwell of California, have joined the chorus, adding their voices to what some describe as a growing, though still limited, movement.

The controversy stems from Mr. Trump’s escalating campaign to purchase or control Greenland, a self-governing Danish territory of strategic importance in the Arctic. On Jan. 19, Mr. Trump announced 10 percent tariffs on goods from Denmark and seven other European nations for deploying troops to Greenland, threatening to raise them to 25 percent by June unless a deal is reached. European leaders have condemned the move as coercive, and some U.S. lawmakers warn it risks fracturing NATO alliances.

Mr. Trump’s leaked message to Mr. Støre reportedly linked the Greenland push to resentment over the Nobel Peace Prize, awarded in December 2025 to figures involved in global diplomacy unrelated to Mr. Trump’s administration. “I do not feel an obligation to think purely of Peace,” Mr. Trump allegedly wrote, according to reports. The White House has dismissed the calls as “political drama” and denied any instability.

Legal experts emphasize that invoking the 25th Amendment is a high bar. Section 4 requires the vice president and a majority of the cabinet (or a congressional body) to declare the president unable to serve, triggering a potential transfer to the vice president. Congress then has 21 days to resolve the matter with a two-thirds vote in both chambers if the president contests it. The amendment has never been used to remove a president, though it was discussed during Mr. Trump’s first term after Jan. 6, 2021.

Republicans have largely rejected the idea, with no indications of cabinet support. Some, like Senator Thom Tillis of North Carolina, have criticized Mr. Trump’s tariffs but stopped short of questioning his fitness. The push remains confined to a handful of Democrats, with no formal resolution or vote scheduled.

The Greenland dispute has broader implications, including threats to transatlantic ties. Mr. Trump has refused to rule out military options, prompting European nations to bolster Greenland’s defenses. Protests in Nuuk, Greenland’s capital, have opposed U.S. involvement, with Prime Minister Jens-Frederik Nielsen affirming loyalty to Denmark.

As midterm elections approach, the calls may serve as a rallying cry for Democrats but face long odds in a Republican-controlled Congress. The White House did not respond to requests for additional comment.