linchpin

The tariffs against Canada and Mexico upend a trade pact that dates back three decades and is the linchpin of many tightly integrated industries across North America.

He’s also a linchpin to what happened to compensate once-imprisoned Japanese Americans.

The mango, that beloved linchpin of cuisines and cultures around the world, typifies this trend.

Another linchpin of retirement, a Social Security check, may not be as hefty in the next decade if the program's funds aren't shored up by Congress.

In the Senate, he has been a linchpin for bipartisan legislation on issues as eclectic as electoral reform, pandemic-era economic relief, marriage rights and infrastructure development.