The House and Senate are considering tax legislation that will add $1.5 trillion to annual deficits over the next 10 years, according to their own numbers. This is okay, we're told, because the tax cuts will stoke economic growth, delivering added tax revenue that offsets the rate reductions. Note the bigger point here. Republicans still say they don’t like deficits — but apparently, this particular plan lets them cut taxes without adding more debt. It’s a miracle. Is their claim really true? Will the GOP tax plans boost economic growth? That’s the 1.5-trillion-dollar question. Theory vs. Reality The Republican plan’s...