Your knowlege of electoral history is impressive. But should Selebius win reelection (especially if by a wide margin), she will inevitably be pressured by her party to seek election to the U.S. Senate when Sam Brownback steps down. And she is not a party maverick.
Normally, a sitting Governor is the strongest candidate one find in a race for the U.S. Senate, sometimes even stronger than an incumbent Senator.
So this election is far more important than it initially appears to be (like Ted Strickland's election to Congress in 1992). Conservatives should make it a bigger priority than it currently is.
A lot of Dem Governors have passed on running for the Senate in KS. The presumption is now that she will be reelected despite her "issues" (another issue that ought to be played up is her packing the Courts with radical activists, including the State Supreme Court), but how the electorate will feel about her in 2010 may be a different story from today.
Assuming it's 100% true that Brownback retires, her likely opponent will be Rep. Jerry Moran (Pat Roberts' successor), who is extremely popular. Now the political landscape could lean 1 of 2 ways, and I'll make it simple. If there is a Democrat President in 2010, Sebelius will NOT win that Senate seat, period. If there is a Republican President, she'll have a better shot, but Moran's support cuts across both the regular GOP and the RINO "Moderate" liberal wing, so he will be formidable, regardless.
Sometimes supposedly popular outgoing or recently former Governors are the best candidates, but their records of moving over to the Senate are by no means a guarantee. Kit Bond & Bob Graham in 1986, Tom Carper in '00 (DE) and Evan Bayh & Voinovich in '98 (OH) were some success stories, but Jerry Brown in 1982 (CA), John Evans in '86 (ID), Mike Sullivan in 1994 (WY), Tony Knowles in '04 (AK) came up short.