It's unlikely that President Obama will sidestep a debt ceiling crisis by putting his imprimatur on platinum, trillion-dollar coins. But one House Republican is taking the threat seriously, introducing legislation that would bar the U.S. Treasury from creating the currency.

Rep. Greg Walden (R-Ore.) is pushing against an idea that has gained traction among many liberals, including economist Paul Krugman: The Treasury can mint platinum coins of any denomination, which, advocates argue, would allow the administration to produce enough funds to avoid the $16.4 trillion borrowing limit. The proposal first came up during the 2011 debt crisis.