President Barack Obama appeared at a fundraiser Thursday afternoon to boost Illinois state Treasurer Alexi Giannoulias, the Democrat he hopes will win his former Senate seat in November.

“We need fighters like Alexi in Washington,” Obama told the crowd, according to the White House pool report.

Donors paid up to $2,400 each to see the president at the Palmer House Hilton in the Chicago Loop. Among the high-ranking Democrats who attended were Illinois Gov. Pat Quinn and Chicago-area Reps. Jan Schakowsky and Danny Davis as well as Rep. Debbie Halvorson.

Giannoulias faces Republican Rep. Mark Kirk in the race for the Senate seat that Obama relinquished when he was elected president in 2008. Sen. Roland Burris (D), who was appointed to fill the Senate vacancy, is not running for a full term.

Both candidates carry significant baggage into the fall stretch of the campaign. Giannoulias has defended himself from the fallout of the closure of his family’s bank. Kirk, on the other hand, has had to defend distortions of his military record.

“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,” Obama said, according to the pool report.

He added: “You can trust him. You can count on him.”

During his remarks, Giannoulias repeatedly sought to link Kirk to former President George W. Bush.

“Are we going to send people to Washington to get things done, or will we elect those whose only objective is to obstruct and deny the achievements of the other party?” Giannoulias said, according to the pool report. “That’s what this race is all about.”

Some protesters gathered outside the downtown hotel for the event, and a group of tea party supporters chanted “2012. We can’t wait,” according to the Associated Press.

Obama has a busy schedule in Chicago: Wednesday night he was feted at a 49th birthday dinner that doubled as a fundraiser, and later Thursday he’ll participate in two more fundraisers to benefit the Democratic National Committee.

The president is the latest in a line of administration officials who have come to Illinois to help Giannoulias. Vice President Joseph Biden, White House Deputy Chief of Staff Jim Messina and Education Secretary Arne Duncan all appeared with the Senate candidate in June.