Social media was itself ablaze on Tuesday in response to Trump's tweet, which suggested that burning the US flag should be punishable by a year in jail or a revocation of citizenship.
Trump's provocative tweets on flag-burning and other topics, including efforts to recount the Nov. 8 presidential vote, came as the Republican worked to fill his Cabinet in advance of his inauguration in January.
The US Supreme Court ruled in 1989 that flag-burning was not a crime but rather a form of protest protected by the First Amendment of the Constitution. The high court has also ruled more than once that citizenship cannot be revoked.