Final answer:
The protest movements of the 1960s were led by the counterculture, including hippies, and various New Left movements, which championed alternative lifestyles and radical societal changes such as civil rights and anti-war efforts. The counterculture and New Left supporters were also likely to back the environmental movement. The Silent Majority, on the other hand, preferred traditional values and supported Nixon's strategies for stability and law and order.
Step-by-step explanation:
The groups that led the protest movement in the 1960s were the counterculture, which included the hippies, and various New Left movements. The counterculture offered an alternative to mainstream American values, challenging traditional structures and conventions through lifestyle and behavior. The hippies were a prominent subgroup known for their opposition to the Vietnam War, and embrace of peace, love, and communal living. The New Left was more politically oriented, focusing on radical changes in society and advocating for civil rights, gender equality, and end to the Vietnam War.
Regarding the environmental movement, the groups most likely to support it from the 1960s through the 1980s were those that were part of or sympathetic to the counterculture and New Left movements, as they often promoted ecological awareness and sustainable living as part of their ethos against consumerism and corporate power.
President Nixon's Silent Majority refers to the moderate, mainstream Americans who quietly supported his strategies. These individuals generally opposed the radical societal changes occurring at the time and favored order, tradition, and patriotism, which aligned with Nixon's stance on law and order and governmental stability.