This isn't the first time "archaic laws" like Posse Comitatus have been discussed. In fact, Sen. Joseph Biden (D-DE) said he'd support allowing (U.S.) soldiers to arrest (U.S.) civilians back in 2002. And, here's a related FR thread from that year.
Our wacky, outdated laws! What American desperately needs is a bipartisan team of patriotic Americans to go through our musty, complicated, old laws and change them to match present-day reality. Streamline things, make things easier. And make us all safe!