This was heard on MSNBC’s The Beat with Ari Melber in a discussion of the coronavirus and the White House response.  This is a mashup of “dig in (one’s) heels” (resist stubbornly) and “drag (one’s) feet” (deliberately slow or reluctant to act).  “Dig” and “drag” sound similar and feet have heels so that contributed to the mixup.  A shout out to Frank King for hearing this one.