After a weekend of chaos at airports, mass protests and diplomatic outcries, criticism of Trump's proposal even came from Barack Obama, who broke his silence for the first time since leaving office.
"President Obama is heartened by the level of engagement taking place in communities around the country," Obama spokesman Kevin Lewis said.
"Citizens exercising their constitutional right to assemble, organize and have their voices heard by their elected officials is exactly what we expect to see when American values are at stake."
Obama's foray back into politics will only add to the White House's sense of besiegement. For much of the last 48 hours, the embattled Republican president has been on the defensive.