Rick Santorum's powerful finish in the Iowa caucus is bringing fresh attention to his tenure in Congress, including ethics questions that dogged him about a preferred mortgage he received from a bank run by campaign donors, and federal funds that went to a real estate developer who backed his charity. One of the top donors to Santorum's charity was also the beneficiary of an $8 million Santorum-sponsored federal earmark, according to published reports. Melanie Sloan, a former federal prosecutor who filed an ethics complaint against Santorum in 2006 on behalf of a watchdog group, said her organization's website received a...