Most political insiders expect Barack Obama to win upwards of 60 percent, possibly more, of his home state’s vote against John McCain. But will Obama create a coattail effect for the rest of the Democratic ticket in Illinois?

We asked political prognosticators David Wasserman, of the Cook Political Report, and Josh Kurtz, of Roll Call, a newspaper that covers Capitol Hill, to weigh in on five of the state’s most competitive House races. Democratic victories in these races could tip the balance of power in Illinois’s congressional delegation. Currently there’s an 11-8 split, Democrats over Republicans.

Bill Foster (D) vs. Jim Oberweis (R)
Turns out even some GOPers are hoping to surf the Obama wave. Jim Oberweis’s campaign manager, David From, says their campaign is trying to attract the so-called "OB voter" (Obama-Oberweis voter) for Oberweis’s second run against Foster in the western suburbs. For his part, Foster is rerunning the same ad featuring Obama that helped him win last March’s special election. Obama bounce? Wasserman: "Foster is not a dynamic candidate, but he should be able to take advantage of his opponent’s weakness to get a full term." Kurtz: "Oberweis has tried and failed now four times, even though it’s still a Republican-leaning district. Remember that Obama cut a commercial for Foster, and that probably helped." Prediction: Foster holds on.

Debbie Halvorson (D) vs. Marty Ozinga (R)
State senator Halvorson is counting on a big Obama turnout to beat concrete magnate Marty Ozinga, a contest to replace the retiring GOP incumbent Jerry Weller. Obama bounce? Wasserman: "I see this race as very competitive." Halvorson, he adds, probably gets a two- to three-point boost from Obama. Kurtz: "This district voted slightly for Bush in 2004. I wouldn’t be surprised if Obama wins it this time. Just having that as a fact means there’s more voters inclined to pull the lever for Democrats down the line." Prediction: Halvorson barely wins.

Melissa Bean (D) vs. Steve Greenberg (R)
Bean rode into Congress in 2004 by defeating 35-year incumbent Phil Crane. She got a boost from then U.S. Senate candidate Obama, who ran strongly in her district. Now Bean faces Greenberg, a businessman. Obama bounce? Wasserman: "Two to three points of an Obama bounce here. Melissa Bean is lucky to have him at the top of the ticket." Kurtz: "It’s a pretty conservative district—it went to Bush by 12 points in 2004 and 14 [points] in 2000. It’ll probably be a close race between Obama and McCain, but I think she’ll outpoll [Obama]." Prediction: Bean wins.

Dan Seals (D) vs. Mark Kirk (R)
Seals came within six points of defeating the moderate Republican Kirk in 2006 and is definitely trying to ride Obama’s coattails this election. Lest there be any doubt, Seals says in a TV ad: "Mark Kirk accuses me of supporting the Obama agenda—well, you bet I do." (The 10th is one of only eight GOP-held districts that John Kerry carried in 2004.) Obama bounce? Wasserman: "Obama’s place at the top of the ticket should help Seals. I can’t say it’s the difference maker." Kurtz: "Even Mark Kirk has told us he expects Obama to get 60 percent of the vote in his district. That’s a lot of voters he’s going to have to persuade to vote Democratic for president and then switch over to Republican." Prediction: Tossup, edge to Kirk

Jill Morgenthaler (D) vs. Peter Roskam (R)
Iraqi war vet Morgenthaler is trying to do what Iraqi war vet Tammy Duckworth couldn’t do last election: beat Roskam in this longtime Republican stronghold in the northwest suburbs. Obama bounce? Wasserman: Obama will probably give Morgenthaler a two- to three-point boost, he says, but her association with Governor Rod Blagojevich (she was the Illinois director of homeland security) is a "severe drag on her campaign." Kurtz: "Roskam is very strong in the 6th. Obama at the top of the ticket could make the race closer." Prediction: Roskam wins.