President Obama returned to his adopted hometown of Chicago Thursday to raise money for Illinois state treasurer Alexi Giannoulias, the second time the president has appeared in support of the senate hopeful in the battle to keep Obama’s old seat in Democratic hands.

“Alexi is my friend. I know his character. I know how much he loves this country. I know how committed he is to public service for all the right reasons,” the president said to an audience gathered at the Palmer House Hilton.

But the president’s show of support drew fire from Republicans criticizing the senate candidate’s checkered financial record.

“He’s campaigning for a failed mob banker who loaned money to known criminals and lost $150 million of taxpayer dollars,” NRSC Chairman John Cornyn (R-TX) said in a written statement.

The NRSC today launched a web ad against Giannoulias highlighting the April seizure of his family’s bank, his failure to pay income taxes, and loans to “Jaws” Giorango and Tony Rezko. “Al Capone would be impressed,” a voice intones in the ad. Obama has sought to distance himself from Rezko and Chicago machine-style politics.

Giannoulias’ Republican opponent Mark Kirk has faced his own share of criticism for inflating his experience in the U.S. Naval Reserves.