“Well, Paul Ryan, you’re a free man now,” began the New York Times editorial that appeared on April 11, the day the Wisconsin congressman announced he’d be stepping down as House speaker and leaving Congress in January. Three paragraphs down, the editorial counseled Ryan about how to put his liberation to good use:
You don’t have to worry anymore about weathering a primary challenger from the far right. You don’t have to truckle before a blast of presidential tweets. You can use your remaining authority and credibility with your colleagues to pass legislation to make it harder for the president to fire Robert Mueller, the special counsel, and other officials at the Department of Justice. On your way out the door, on that crucial question, you still have a chance to put yourself on the right side of history.
To truckle before stands out in that paragraph. Its meaning is clear enough in context – something about deference, obsequiousness, sycophancy – but where does it come from?