Congress has 3 options to enforce subpoenas. The first—a civil suit—is a nonstarter; it takes years. The second—a criminal referral to DOJ—only works if you can convince Barr to appoint a Special Counsel to investigate...Barr. The third—an arrest—would go to court, but *quickly*.
1/ One reason an arrest (mind you, it would only be an *attempted* arrest; it would *not* be successful) may be the best option is that issues in criminal law, especially something like an attempted arrest—as opposed to issues in civil law—have to be resolved relatively quickly.
2/ And yes, the House can order its sergeant-at-arms to (physically) arrest someone and hold them in the Capitol until they comply with a subpoena (I know it sounds crazy, but Google it yourself if you doubt me, or watch any interview with a legal scholar on CNN/MSNBC right now).
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