Iowa Senator Tom Harkin is hesitant to support the new republican plan to do away with the so-called “marriage tax penalty” for married taxpayers. Harkin, a democrat, says the tax -does- appear to be unfair. He says he’s worried undoing the penalty may create problems for other taxpayers.Senate republicans have unveiled a ten-year, 240-billion dollar tax cut to eliminate the marriage penalty. That’s much larger than the 182-billion dollar plan already passed in the House. Harkin says the numbers are “too big.”