Since barely winning a hard-fought race to replace his former boss John Porter in 2000, Republican Mark Kirk has enjoyed a relatively stress-free tenure in Illinois's 10th Congressional district. In the 2002 midterm, Mr. Kirk coasted to a victory margin of 38% and he racked up a 28-point win in 2004 even as constituents in his affluent, Democratic-leaning district on Chicago's North Shore voted for John Kerry over President Bush by a margin of 53 to 47.

But this year is a bit different. In addition to facing a hostile political environment driven by dissatisfaction with Iraq and an unpopular president, the moderate Mr. Kirk is dealing with a young but impressive challenger in Democrat Dan Seals, a 35-year-old African-American who many compare to Illinois's junior Senator Barack Obama. Mr. Seals has been boosted by financial support from the left-wing "netroots" crowd, and he's also gotten significant organizational help from Democrat Jan Schakowsky from the neighboring 9th district who is facing only token opposition this year.

Democrats have been insisting for weeks that the district is in play, and on Tuesday the DCCC finally put its money where its mouth is by committing more than $25,000 for two direct mail pieces during the final week of the campaign.

But Republicans in the district are confident Mr. Kirk will prevail -- though admittedly not with the victory margin he's achieved in past races. Mr. Kirk has a well-deserved reputation for being a moderate and a record of achievement in the district that (coupled with a decided money advantage) Republicans believe will sufficiently insulate him against the negative political environment.

It's hard to see Mr. Kirk being swept from office by anything less than a huge Democratic wave. But that's exactly what many Democrats believe is coming next Tuesday.