Senators who were there remembered 1997, when the new, Harvard-educated law professor from Hyde Park beat the party bosses to join their ranks.
"Before he was even sworn in, somebody came to me and said, Can you believe this guy wants to be president of the United States?" said State Sen. James Clayborne, (D) Belleville.
In fact, the Democrat Obama reportedly had drawn so much skepticism from his own party during that first term that his best friend in the state senate was DuPage County Republican Kirk Dillard.
"I am blessed and feel free very proud that I got to work with this very exceptional gentleman long before the crowds got to know him," said State Sen. Kirk Dillard, (R) Naperville.
Obama's standing among Democrats fell even more in 2000 when he challenged Congressman Bobby Rush and lost. It wasn't until 2003 that things looked up again when his party regained control of the Illinois State Senate and Emil Jones was elected president.
"He said, You have the power to make a United States Senator...I said, Yes, do you know of anyone I can make? And Barack said, Me," said Emil Jones, (D) former Illinois Senate president.
Barack Obama was in the U.S. Senate only two years before he began his campaign for president. Compare that to eight years in the Illinois Senate, where members take credit for helping the president-elect develop his winning political style.
"Everything he's doing now we saw him do that in the Illinois assembly: bringing people together, working with the Republicans, being a moderate," said State Sen. John Cullerton, (D) Illinois Senate president.
"Barack Obama came out of the Illinois Senate a stronger person, and he's gone from a state senator to a real statesman," said Trotter.
ABC7's Charles Thomas counted nearly two dozen Illinois senators Monday who have made the trip to Washington to watch the inauguration of a man they still count as one of their own.