I’m the first millennial Republican to run for US president. If you ask most people my age what it means to be an American today, you get a blank stare in response. Faith, patriotism, family and hard work are disappearing. A recent Wall Street Journal survey reveals that young people in particular are responsible for driving this trend: 59% of Americans age 65 and older say that patriotism is “very important” to them, compared with only 23% of adults under age 30. The survey observed a similar gap with respect to interest in religion, hard work and having children. This...