This piece is written by a (flat-tax) lobbyist ("Katie McAuliffe is federal affairs manager at Americans for Tax Reform."), which is very clear when you read sentences like:

  "They want the MFA passed not for sales tax collection,
  which has been on the rise, but to set a precedent for 
  exporting their taxes and laws across their borders so they 
  can tax and regulate people who cannot vote against them."