The Hill: Sen. John Thune (R.-S.D.) introduced the Senate version of a bill that would make it easier for those who voluntarily wanted to pay higher taxes to do so - a tongue-in-cheek jab at President Obama's proposed "Buffett Rule" that would eliminate tax loopholes for the wealthiest Americans. Thune introduced "The Buffett Rule Act of 2011" (S.1676), which would require the I.R.S. to provide a line on tax return forms inviting taxpayers to donate to the federal government. Any donations would be placed in a fund dedicated to paying down the national debt. A similar version of the bill was introduced last week in the House.