Except for the affair, ethics probe and no money, Nevada's GOP Sen. Ensign was a certain 2012 victor | Top of the Ticket | Los Angeles Times

Political commentary from Andrew Malcolm

Nevada Republican Sen. John Ensign, a Christian who preached strong family values until about the time he admitted a sexual affair with a former aide who was married to a current aide whom he then helped get lobbying work, says he's putting his family ahead of his own career by deciding to retire next year.

Other factors that may have had something to do with the 52-year-old ex-veterinarian's surrender to political reality are: an ongoing Senate Ethics Committee investigation, a distinct lack of money, zero support from fellow GOP senators, a growing array of challengers, a high unfavorable rating and his name atop the list of most vulnerable 2012 incumbents.

Other than that, the former House member would have been a shoo-in for a third Senate term. Ensign said his self-imposed troubles had "zero effect" on his decision. So, add that whopper to the list of reasons he's gone.

Ensign's overdue departure sets up an even more interesting national ....

... Senate election scenario. The usual number of 33 Senate seats are up for election on Nov. 6, 2012, just 609 days from now.

However, 23 of those seats must be defended by Democrats. And due to retirements, eight of the 33 (including five now held by those who caucus with Democrats) will now involve no incumbent.

In Ensign's case, as Jennifer Duffy points out, his departure is actually good news for Republicans because it creates a tossup instead of a surefire annihilation in the unlikely event Ensign had survived a mounting primary challenge by Rep. Dean Heller.

The other two GOP retirements are Kay Bailey Hutchison of Texas and Jon Kyl of Arizona, and neither seat should be too hard to hold.

Given the growing strength of Republicans in the South the last few years, Florida Democratic incumbent Bill Nelson could be in trouble. President Obama opened his 2012 fundraising drive Friday night with two money events in Miami for Nelson, who turns 70 next year.

This is a very good time to be strong in the South, which shows the most gains in House seats (and electoral votes) following the 2010 census. Republican Texas gains four seats and Florida two. Georgia, South Carolina, Arizona, Utah,  Nevada and Washington gain one each. 

States losing House seats include the traditional Democratic strongholds of New York, Massachusetts, New Jersey and Pennsylvania, along with Illinois and Louisiana.

But those kinds of changes really matter most only in presidential election years, which 2012 -- oh, wait -- is.