Labor Secretary Tom Perez, who's been talked about as a potential running mate for Hillary Clinton, gave an impassioned speech defending immigrants, and he quoted a famous poem about Nazism to encourage Americans to stand up against anti-immigrant impulses.
Though he didn't mention Donald Trump by name, the presumptive Republican nominee was clearly on Perez's mind.
"History will soon ask where we were in the face of unrelenting attacks on immigrants, unrelenting attacks on our Muslim brothers and sisters, unrelenting attacks on voting rights," Perez said at a conference for national Latino elected officials Thursday. "History will ask if you spoke up for the rights of people who didn't look like you."
Trump, in the speech that launched his campaign, referred to Mexicans crossing into the U.S. as "rapists," and, after the San Bernardino mass shooting last year, he called for a Muslim entry ban, a call he renewed after the Orlando massacre a week and a half ago.
Perez then went on to quote Pastor Martin Niemöller -- whom he described as "someone who opposed Nazi Germany and Hitler" and who he said "sings to the challenges of today."
"First they came for the Socialists, and I did not speak out because I was not a Socialist," Perez said. "Then, they came for the Trade Unionists, and I did not speak out because I was not a Trade Unionist. Then they came for the Jews, and I did not speak out because I was not a Jew. Then they came for me, and there was no one left to speak for me."
Niemöller's poem has come up before this election cycle -- late last year, the super PAC supporting Ohio Gov. John Kasich's presidential candidacy released a web video that used the Niemöller to explicitly and ominously warn of the potential danger of a Trump presidency.
Perez's defense of immigrants also came as the Supreme Court returned a disappointing ruling for the White House on the president's 2014 immigration executive actions, which would have extended the benefits of the DACA program to millions more undocumented immigrants.
The labor secretary rounded out his speech with themes the presumptive Democratic nominee returns to often in her campaign speeches -- "building bridges, not walls" and emphasizing optimism over fear.