Is Obama Sailing "Parlous" Seas? Like...um...a Pirate?

Writing in Politico about recent missteps by President Barack Obama, journalists John F. Harris and Todd S. Purdum used parlous, a little-seen shortened form of perilous, when they wrote: 

But it’s also true, as acknowledged even by sympathetic lawmakers and some former Obama West Wingers in recent background conversations, that his presidency is in a parlous state, with wounds that are lately self-inflicted.

Like perilous, parlous means "dangerous" or "fraught with peril" and is not a word you see every day. In fact, a quick check on the Google Ngram Viewer shows that after a brief spike in popularity around the turn of the 20th century, parlous has been in decline since 1930. The Ngram Viewer also shows that of perilous and parlous, perilous is overwhelmingly the adjective of choice.

So why parlous? Why now? Tomorrow is International Talk Like a Pirate Day. Perhaps in homage to this much-loved event, the Harris and Purdum duo had stormy seas, mutineers, and p-arrr-lous adventure on the brain.