President Obama returned to work yesterday to find deeper fears of a return to recession. So it was somewhat fitting that, when he stepped to the microphone to address those concerns, it didn’t seem to work. “How’re we doing on sound, guys?’’ he asked the gathered press. Not that well, actually. It is now understood by everyone, apparently including the administration, that Obama did a poor job explaining last year’s stimulus package. And with many of its programs starting to expire, it may not be worth the breath to try to explain it now. Rather, Obama needs to lay out a post-stimulus economic plan. The hints offered yesterday — extending the Bush tax cuts for the middle class, taking more steps toward a clean-energy future — were neither new nor inspiring. And Obama’s slumping body language couldn’t have looked less confident if he were dragging a coffin. Yesterday’s remarks were meant as a precursor to more fully developed economic talks in the near future. Hopefully, by then, his bad-mike day will be only a bad memory.