Speaking to a joint meeting of Congress, King Charles made the case for a continued British-U.S. cooperation, including a strong NATO alliance despite attacks on the treaty from Donald Trump and broader calls for American isolationism.

The king and Queen Camilla, on a visit to the United States to mark the 250th anniversary of the Declaration of Independence, also addressed the shooting on Saturday at the Washington Hilton, where Trump and top administration officials were attending the White House Correspondents’ Association Dinner.

Calling the assassination attempt the “incident,” Charles told the packed House chamber, . Let me say with unshakeable resolve: such acts of violence will never succeed. Whatever our differences, whatever disagreements we may have, we stand united in our commitment to uphold democracy, to protect all our people from harm, and to salute the courage of those who daily risk their lives in the service of our countries.”

Charles’ speech drew heavy turnout on both sides of the aisle, unlike Trump’s State of the Union speech, which saw some empty seats on the Democratic side.

Charles did not mention Trump by name, and he generally avoided diving into the partisan fray.

Yet some of his lines took on different meaning given the rancor on Capitol Hill, including Democrats’ calls on Republicans to hold Trump in check.

“Our Declaration of Rights of 1689 was not only the foundation of our constitutional Monarchy, but also provided the source of so many of the principles reiterated – often verbatim – in the American Bill of Rights of 1791. And those roots go even further back in our history: the U.S. Supreme Court Historical Society has calculated that Magna Carta is cited in at least 160 Supreme Court cases since 1789, not least as the foundation of the principle that executive power is subject to checks and balances.”

The comment drew a standing ovation on both sides of the aisle, and some laughs among Democrats.

Much of the speech, though, was reminding lawmakers of the strong bonds the two countries have had, including through NATO.

“We do not embark on these remarkable endeavours together out of sentiment. We do so because they build greater shared resilience for the future, so making our citizens safer for generations to come,” the king said.

He also talked about one of his chief concerns: The environment.

“We ignore at our peril the fact that these natural systems — in other words, Nature’s own economy —provide the foundation for our prosperity and our national security,” he said.

The comment also drew a standing ovation, but largely on the Democratic side.