I haven't flown since shortly after you had to take off your shoes to get through security, taking Amtrak instead, and I've only ever even seen two people searched by TSA. You barely even see them, and if you do, they're usually sitting around looking bored.

I suspect that they only bother to do the random searches if they've gotten some specific alert or warning.

Many, many trips between Chicago and SF, Portland, and Texas, or rather, California Zephyr, Empire Builder, Texas Eagle, and Spirit of New Orleans etc. Haven't had any need to go through Bloombergville, though so ymmv.