CHICAGO (Reuters) - Buoyed by their surprise Senate victory in Massachusetts, Republicans in President Barack Obama's home state of Illinois sense the Senate seat he left vacant is ripe for their picking come November elections.
Obama's Democrats have long dominated Illinois politics. But Republicans view their man Scott Brown's capture in January of the late Edward Kennedy's seat in Massachusetts as a sign of voter dismay with Democrats in the White House and Congress.
Public opinion polls ahead of Tuesday's party primaries in Illinois show five-term U.S. Representative Mark Kirk likely to win the Republican nomination easily.
Favored to win the Democratic primary and face off Kirk for the vacant seat is Alexi Giannoulias, Illinois treasurer and Obama's basketball-playing buddy.
"The Democratic candidates are second-tier. They're not particularly exciting, not particularly experienced," DePaul University political analyst Michael Mezey said.
Kirk has lent his own twist to Brown's best-known line in the campaign, saying: "This is not Obama's seat, it's the people's seat."
One poll showed Kirk trailing Giannoulias if the two face off -- but only narrowly. That's a far cry from the 62 percent of Illinois voters who cast ballots for Obama against 37 percent for the Republican John McCain in November 2008.
Because Kirk has been in the House of Representatives since 2000, and because of his moderate stances on some issues, he is less able to take advantage of the anti-incumbent fervor among some voters that likely helped Brown.
"Kirk is not the kind of candidate to get the Tea Partiers' blood running," Mezey said, referring to a nascent movement of fiscal conservatives. "He's a moderate, middle-of-the-road candidate. He's been pro-choice, pro-gay rights, anti-gun."
Roosevelt University political analyst Paul Green said: "These Tea Party guys are riding high right now. But Illinois is a coffee state; there aren't going to be a lot of tea drinkers here."
What had once been considered a safe Senate seat for the Democrats, the vacant Illinois seat has become one of five "toss-up" races where Democrats are in danger of losing, according to the Cook Political Report.
Two other Senate seats where Democratic incumbents are not running again -- in Delaware and North Dakota -- are likely to switch to the Republican column, while four Republican-held Senate seats are considered toss-ups, the Cook Report said.
Each party has 18 Senate seats up for election. Republicans now hold 41 and Democrats 57, with two independents usually voting with the Democrats in the 100-seat chamber.
Brown's victory cost the Democrats their 60-vote threshold that had permitted the party to overcome Republican procedural roadblocks.
Over the past 40 years, Illinois has had seven Democratic and two Republican U.S. senators -- the last Republican was moderate Peter Fitzgerald who retired in 2005 after just one term. Democrats hold all major state-wide offices and are in the majority in both houses of the Illinois legislature.
Recent political setbacks for Democrats include an indicted and impeached governor, Rod Blagojevich, and a state government seemingly paralyzed by expanding budget deficits.
Blagojevich's corruption trial is set to begin in June, making headlines as the Senate campaign gets into full swing.
"The Illinois seat is going to be top of the Republican priority list, not for symbolic reasons that it's Obama's home state, but because it's one of the most likely seats for them to win," said political analyst Dick Simpson of the University of Illinois at Chicago.
Simpson predicted an expensive, bruising campaign for the seat occupied by Roland Burris, a Blagojevich appointee who is not running. Among the charges against Blagojevich is that he tried to sell the seat after Obama was elected president.
Editing by Mohammad Zargham and Howard Goller