I just got my passport card on Thursday, in time for a weekend trip to NYC. The ID-checker at LAX on Friday didn't say a word. Yesterday at JFK, lady puzzled over it and called someone else over. My attitude toward TSA employees is always a mirror of what their own, and the guy I spoke to about it was friendly, so I was polite in return. He said their management had told them not to accept passport cards, but they (three of them, including a three-stripe supervisor) seemed to agree that it was, in fact, me on the card and let me through without further delay. I encouraged him to have his management double-check with the higher-ups about the passport card, and he said he would mention it.
Pretty sad state of affairs when my kudos to a TSA employee comes from him not being a ......... After years of TSA bs my expectations have sunk that low.