Strategically, they start with cases the public is more likely to support, and then the precedent, law, norms, mechanisms, etc. are all there to take it further. Another common step is demonization, in this case of anything Chinese, TikTok, and, to a degree, of anything not 'American'.

Look at oppression of unpopular groups. They've started with groups, such as undocumented immigrants and trans people, already unpopular groups and easy targets. They demonize them extensively and make oppression acceptable to the public. Now there is precedent; by now, people don't even object to it on the grounds of human rights, justice, or humanitarianism; stereotype, prejudice, and hatred are no longer taboo. Soon there will be camps, a police force accustomed to and trained in mass arrest, and a public accustomed to it as a legitimate mechanism.