The AP is reporting this morning that Senate Minority Whip Trent Lott of Mississippi will resign his seat before the end of the year. Lott holds the number-two post on the Republican leadership ladder, behind Minority Leader Mitch McConnell of Kentucky. The remainder of the five-member GOP leadership team, in order of rank, is Jon Kyl of Arizona, and Texas’s two senators, Kay Bailey Hutchison and John Cornyn.

I made some calls this morning and here is the picture:

There are two scenarios. The most likely is that everybody moves up one notch. Kyl would become Whip, a job for which he is well suited. He’s a behind-the-scenes player with a reputation as a media-averse insider. Hutchison would become chair of the Republican conference, with responsibilities for messaging. Cornyn would take over Hutchison’s current job as chair of the Republican Policy Committee. Both Hutchison and Cornyn would be better suited for the new jobs than for their old.

The other scenario is a run for Whip from outside the leadership — most likely by Lamar Alexander of Tennessee. Alexander previously ran against Lott and lost, reportedly by one vote. Alexander is regarded as a moderate in a caucus that is very conservative, but leadership races are often decided by personal factors. Many Republicans will regard Alexander as having the first claim on the job, especially since Lott bailed out after serving less than a year, and even more especially since the word is that the reason Lott is leaving is that new ethics rules would double the waiting period before he can lobby. Smarmy to the end.

It is unlikely that Hutchison or Cornyn will challenge Kyl. Hutchison has said that she will not seek a third term in 2012 and that she might step down early to run for governor. (The worm in this apple is that Perry might leave early too, allowing Dewhurst to move up and Hutchison to decide whether to challenge an incumbent governor.) Cornyn doesn’t appear to be interested either. He and Kyl are friends, and his prospects for advancement are excellent, with Hutchison’s pending departure. The only downside for Cornyn is that the more visible he gets, the greater the incentive for the national Democratic party to try to knock him off in 2008.