Fueling speculation that failed 2006 Congressional candidate Tammy Duckworth (D) is the frontrunner to replace Sen. Barack Obama (D-Ill.) if he is elected president, Illinois Gov. Rod Blagojevich (D) hosted a Denver bash on Tuesday night for the disabled Iraq War veteran.

The event was held as Illinois political insiders feverishly try to predict who would be appointed to the Senate if Obama goes to the White House. An array of scenarios exist.

“Everyone has been playing the guessing game and the governor has been in a bunker, so in the absence of any information, it’s an interesting development,” an Illinois Democratic operative said of the Denver party.

The speculation comes during a period of unusual uncertainty in Illinois, a state with a tradition of bare-knuckle politics and political deal-making.

Blagojevich on Tuesday afternoon confirmed he would host a party for Duckworth, but he denied that he’s made up his mind and said the party was not necessarily a sign of things to come.

“I’m going to wait and see how things shake out,” Blagojevich said. “I’m a Cubs fan, so I don’t jinx anything.”

Under Illinois law, an Obama victory in November would charge Blagojevich with naming a successor to serve out the remaining two years of Obama’s Senate term. Duckworth, a hand-picked candidate of then- Democratic Congressional Campaign Committee Chairman Rep. Rahm Emanuel (Ill.), lost last cycle to Rep. Peter Roskam (R) in a marquee race that cost almost $8 million.

Obama, Blagojevich and then-Senate Minority Whip Dick Durbin (D-Ill.) also made high-profile endorsements of Duckworth’s 2006 campaign, an ultimately unsuccessful political proxy war with then-Speaker Dennis Hastert (R-Ill.), who represented a neighboring district.

After her 2006 loss, Blagojevich named Duckworth the state’s director of Veterans’ Affairs, a post she still holds.

Duckworth also is considered close with famed Illinois political consultant David Axelrod, who developed her 2006 media strategy and is now the top strategist for Obama’s presidential campaign.

Duckworth’s rocketing to the top of the governor’s list undoubtedly came as a blow to Rep. Jan Schakowsky (D-Ill.), who said in an interview that she is “not strategizing” about — but is obviously lobbying for — the potential Obama vacancy. At a Tuesday morning breakfast of the Illinois delegation to the Democratic National Convention, Schakowsky said she does not “know what to make” of last night’s public feting of Duckworth by the governor.

“I’ve made it clear that I would be honored and pleased” if named Obama’s successor, Schakowsky said. “Tammy and I are great friends, but I don’t know what to read into it and what it really means.”

Duckworth’s apparent jump to the top of Blagojevich’s list of possible replacements also stands to rile a handful of other prominent Illinois Democrats who are said to be interested in the job, a list that includes retiring state Senate President Emil Jones, Illinois Secretary of State Jesse White, and Reps. Jesse Jackson Jr., Danny Davis and Luis Gutierrez.

While names of potential Senate appointees are bandied about, Blagojevich’s own political future is in doubt as his poll numbers decline and insiders wonder whether he’ll seek a third term in 2010 — or even remain in office through the end of his term.

State Attorney General Lisa Madigan (D) is already taking steps to run for governor in 2010, and Lt. Gov. Pat Quinn (D), state Treasurer Alexi Giannoulias (D) and state Comptroller Dan Hynes (D) are also mentioned as possible candidates. Another potential big name is Bill Daley, the former U.S. Commerce secretary and brother of Chicago Mayor Richard Daley (D).

An even more intriguing scenario has Obama abandoning his Senate seat to run for governor in 2010 if he loses the presidential election this fall.

Although many of the potential Senate appointees are African-American, an Illinois Democratic operative said neither race nor political muscle alone are likely to be the deciding factor if Blagojevich is charged with replacing Obama, only black Senator.

“It’s strikes me as counterintuitive to characterize the seat exclusively” as African-American, the source said. “It’s not a question of who has the greatest political connections in Springfield, it’s who can make the strongest case to Gov. Blagojevich.”

Once considered a leading candidate to replace Obama, his one-time protégé, Jones, who recently announced his retirement from the Legislature, refused on Tuesday to discuss a potential successor to Obama.

“I’m not interested in anything right now. There are always people that self-promote themselves [and] I don’t get involved,” Jones said. “I do have ideas, but I’m not going to do that right now.”

Gutierrez on Tuesday also beat back suggestions that he is working delegation rooms this week in the hope that the governor may name him to a vacant Senate seat.

“It would be a distinct honor and a great privilege to serve the state of Illinois in the Senate,” Gutierrez said. “But I am not campaigning during this convention for anything other than to elect Barack Obama president of the United States.”