It's a political commentator's nightmare but experts say it shouldn't be as much of a problem in a general election that such a similarity would pose in a primary.
The name game is an old political ploy in this state. Earlier this year, in fact, rivals of Rep. Jesse L. Jackson Jr., the son of the civil rights leader, tried to derail his re-nomination by putting up a political neophyte named Jesse Jackson -- and even gave him a bogus middle initial to match, claiming his family knew him as Jesse Lee. Public scrutiny prompted the interloper to re-think his candidacy.
But Jackson's rivals weren't the only ones playing games. Observers believe Jackson recruited Anthony Williams for the ballot, to siphon support from his rival's choice, Yvonne Christian-Williams.
Not to worry. Jackson garnered 85 percent of the vote.
Like Jackson, Durbin is a well-liked incumbent. He hails from the East St. Louis area but made his congressional debut in the House district covering Springfield in 1983. He moved to the Senate in 1996 and since has developed a reputation for "bringing home the bacon."
Kent Redfield, a professor of political science at the University of Illinois-Springfield, said the similarity between Durbin's name and that of his challenger likely won't do much to confuse voters.
"Durbin's people have to pay attention to making that distinction (between the names)," Redfield said. "Senator is pretty high profile. Voters tend to have less confusion about who is running at the top of the ticket than the bottom of the ticket."
Nevertheless, more of Durbin's $3.5 million war chest will have to be devoted to the name issue than if he were running against a candidate named Jones.
With Republicans setting their sights on recapturing control of the Senate, one might think the Durbin-Durkin contest would be a tasty morsel.
But, Redfield said, the local GOP likely will concentrate on retaining the governor's mansion and trying to keep the state Senate out of the Democrats' clutches and as for national support, it's a Catch-22.
"You don't get national money unless you're a factor and it's unlikely Durkin will be a factor without national money," Redfield said. "Illinois is an expensive state to campaign in. If this were South Dakota or North Dakota, it would be a different story."
But Allen Fore, executive director of the Illinois Republican Party, said he expects to see national support for Durkin.
"We had a very good victory luncheon today. We had calls from the White House. I think this race is being looked at and targeted for the fall election," Fore said, downplaying the similarity in names.
"The names are similar but the messages are very different," he said.
Dan Allen, spokesman for the National Republican Senatorial Committee, said Durkin is a serious candidate and the name won't be the deciding factor in the amount of support the party provides.
For their part, Durbin's people don't appear too worried.
"There are many more differences between Durbin and Durkin than a 'b' and a 'k,'" said Stacy Zolt, Durbin's campaign spokeswoman.
"The most recent Mason-Dixon poll showed Durbin has 93 percent name identification statewide. We believe that poll to be accurate."