Critics of Mr. Trump on both sides of the Atlantic have called the meeting an indignity for the monarch, who has met every president since Harry S. Truman, save for Lyndon B. Johnson. “Imagine her revulsion and sadness when her dignity is assaulted by the presence of an American President who represents a spectacular degeneracy of the virtues she embodies,” Steve Schmidt, who advised John McCain’s 2008 presidential campaign and recently left the Republican Party, wrote on Twitter.
More than 50 British organizations are involved in the protests, which aim to dog the president at nearly every stop of his visit.
“There has never been a president as bad as Donald Trump,” John Rees, a leader of a group called the Stop War Coalition, said in Regent’s Park, where protesters thronged outside metal barriers as men in suits, wearing sunglasses and earpieces, stared back silently.
“The man is a wrecking ball!” Mr. Reed shouted. (“He’s a criminal!” the crowd shouted back.) “He’s a wrecking ball for peace and justice in the world!” (“’Cause all he cares about is money!” they replied.)
The protests outside Blenheim Palace continued even as Mr. Trump, Mrs. May and around 150 guests dined on Scottish salmon, Hereford beef fillet and strawberries with clotted-cream ice cream. Mr. Trump and Philip May, the prime minister’s husband, wore tuxedos, while Mrs. May wore a sleeveless red gown, and Melania Trump, the first lady, wore a pleated pale yellow gown.
On Thursday evening, Together Against Trump, an umbrella organization, planned a “wall of sound,” with a relentless stream of slogans, whistles, banging of pots and drums to disrupt the visit, even though they were kept sufficiently far away from Winfield House, the ambassador’s residence, to make it difficult to keep the president awake.