Supporters as well as opponents of the war in Vietnam took to the streets, as these New Yorkers did in support of the U.S. invasion of Cambodia in May 1970. Construction workers — called “hard hats” — and other union members marched with American flags and posters championing President Nixon’s policies and blasting New York mayor John Lindsay for his antiwar position. Paul Fusco/Magnum Photos, Inc.

READING THE IMAGE: What do the hard hats in the photograph symbolize in terms of identity and politics?

CONNECTIONS: How were these union members related to the unraveling of the Democratic Party coalition?