(CNN) -- The Democratic state treasurer and a five-term Republican congressman will face off in November to fill the U.S. Senate seat once held by President Obama.
Front-runner Alexi Giannoulias faced criticism after his family's bank came under federal scrutiny. But he beat fellow Democrat David Hoffman, a former Chicago official in charge of trying to root out corruption, by a small margin.
Giannoulias, the son of Greek immigrants, was able to raise money and come out on top in a crowded Democratic field.
"The voters of Illinois are sending a message, and I hear them them loud and clear. In the midst of this dreadful economic crisis, they want a senator who will fight to limit the power of Washington special interests," Giannoulias said Tuesday night at his victory rally.
Some experts said Giannoulias will need to wage a stronger general election campaign than he did in his primary effort to beat his Republican opponent, U.S. Rep. Mark Kirk, in November.
Kirk, who stressed the need to control federal spending and how he would bring an independent mindset to the job during his campaign, easily defeated his GOP rivals.
Speaking to supporters Tuesday night, Kirk emphasized the messages of how Democrats control too much of the government at all levels, the need for more efforts to root out political corruption and the need for fiscal restraint.
"One political party should never hold all of the power," Kirk said. "We reject corruption. We embrace reformers."
Political experts said they believe Kirk, who has a moderate voting record on social issues but considers himself a fiscal conservative, will wage a strong campaign and has a good chance of capturing the Senate seat.
"Democrats right now are in disarray in Illinois," said columnist and longtime political observer Russ Stewart. "Kirk is a moderate. He certainly would appeal to ... independent and suburban voters."
Both Kirk and Giannoulias are trying to position themselves as the best candidate to stand up against special interests and be an independent voice.
The Illinois governor's race was far from resolved Wednesday morning.
Democratic Gov. Pat Quinn, who succeeded now-indicted Rod Blagojevich, led challenger Daniel Hynes by about 7,000 votes, with 1 percent of precincts left to be counted.
On the Republican side, only 500 votes separated Bill Brady and Kirk Dillard, both tied with 20 percent of the vote in a seven-man field. Andy McKenna had 19 percent, with 99 percent of precincts reporting, some 8,000 votes behind Brady.
The Senate position, which Democratic Sen. Roland Burris now holds, has been the subject of controversy since Obama's election. Blagojevich is facing federal charges of allegedly trying to receive financial favors in exchange for an appointment to the seat. He has said he is not guilty, and his trial is expected to begin in the midst of the campaign.
Burris, whom Blagojevich appointed to fill Obama's seat, has been tainted by his ties to the former governor.
It would be symbolic if the Illinois seat and one formerly held by Vice President Joe Biden in Delaware moved to the GOP side, some analysts said.
"Illinois is Obama's seat; Delaware is Biden's seat. Those two seats could go Republican just like Al Gore's seat [in Tennessee] back in 1994 went Republican as well," Stewart said. "It's a symbolic repudiation of the administration."
Besides local issues, several voters cited national issues such as the deficit as the most important and voiced to varying degrees frustration with the national parties.
"I think in Illinois it's hard to trust our local [politicians]because there's been so much corruption, and I know that our deficit is huge and I guess it echoes all the national issues as well, but I feel like in my own state I would like to have some new people that I hopefully can trust this time," Randi Bauer said after voting for Hoffman in the Democratic Senate primary.
Conservative C.J. Quehl, who supports the Tea Party movement, said too many people in Washington depend on government to solve the nation's problems.
"I think the Democratic Party, well definitely led by this current administration, firmly believes that government is the solution to everything, and I'm a part of a fair majority of the people that I run into here that government is not the solution," Quehl said, "so I think predominantly if you had to put a percentage on it, it'd probably be 60-40 Democrat-Republican. But, man, they're both to blame, absolutely."
Construction worker Dave Waller, who voted Democratic but said he likes some ideas Republicans push, said taxes were a key issue, but he's also concerned about the growing federal deficit.
"I think more about deficits and that right now the more deficits, the less tax base, the less money there's going be for programs, after-school programs, anti-gang prevention programs, things that affect our community-housing, food stamps. These are the programs that are major issues in my mind."