I'm an Italian citizen. I came to the USA on a tourist visa 2 years ago but overstayed. I only have my Italian passport with me. Should I be fine flying within the US with no worries? Is anybody going to ask me for my immigration status? I'm very scared.
For a domestic flight in the US, there are no routine immigration checks during checkin or arrival. The airline staff are not qualified to check your immigration status, they just need to see your passport for identification. Similarly, the TSA will check your passport for identification purposes.
There was an incident in 2017 where immigration officers checked the identification of every passenger coming off the flight. In this case, they were looking for somebody specific and had reason to believe they were on that flight (however, they were not).