Senator Lugar said the fair tax plan frees up capital for individuals and businesses.
Daniels says Republicans and their eventual nominee need to offer serious proposals to combat a ballooning national debt.
President Barack Obama has rescheduled a visit to Allison Transmission for Friday.
Allison’s new facility uses the kind of alternative technology Obama sees as a chance to reduce U.S. oil imports by one-third by 2025.
President Obama and Vice-President Biden are visiting Kokomo on Tuesday.