Senator Lamar Alexander, R-Tenn., announced this morning that he is leaving his leadership post among Republicans in the senate.

Alexander will step down in January Chairman of the Senate Republican Conference – the third ranking Republican in the Senate. He said he does plan to run for reelection to the senate in 2014, but not seek another leadership post.

“Stepping down from the Republican leader will liberate me to spend more time trying to work for results on issues that I care the most about,” Alexander said on the Senate floor this morning, “I want to do more to make the Senate a more effective place to address serious issues.”

A former presidential candidate and governor from Tennessee, Alexander has at times broken with the rest of the Republican leadership. He endorsed a proposal from the bipartisan “gang of six” for instance, which would have raised taxes as well as cut spending.

But today Alexander argued that while he is leaving his leadership post, he is not leaving his party.

“I am a very Republican Republican,” he said on the senate floor. “I intend to be more, not less, in the thick of resolving serious issues.”

Alexander argued against those that say the Senate is now more fractious and divisive than it has been in the past. He said that those who say that have no sense of American political history.

“The Senate is created to be the place where the biggest issues producing the biggest disagreements are argued out, and I don’t buy for one minute that these disagreements create some sort of unhealthy lack of civility in the United States Senate.” Alexander said, “to suggest that we should be more timid in debating the biggest issues before the American people would ignore the function of the senate and would ignore — and would ignore our history. the truth is that united states senators debate divisive issues with excessive civility.”

Alexander’s exit from the Republican leadership opens up a few slots for new blood in the leadership.

Senator Thune, R-SD., almost immediately, announced this morning that he will run for Alexander’s post.

“At this time I am announcing my intention to seek the support of my Senate Republican colleagues to serve them as the next Chairman of the Senate Republican Conference,” Thune said this morning, “America is at a crossroads with record deficits and crippling debt, high unemployment, and growing economic uncertainty. Now more than ever it is crucial for Republicans to communicate a clear vision to the American people.”

Thune currently has the 4th post as Chairman of the Republican Policy Committee. Alexander had also talked before in the past about running for the Senator GOP Whip against Senator John Cornyn, R-TX., that was to be opened up with the retirement of Senator Kyl, R-AZ. So the Whip race will now be one to watch as well.

Shortly after, Senator John Barrasso, R-Wyo., announced that he will run to replace Thune’s position as Chairman of the Senate Republican Policy Committee, should Thune move up as expected into the #3 spot.

“Our country faces a wide range of challenges that will require aggressive and conservative policy leadership,” Barrasso said in a statement this morning, “As Policy Chairman, I will work with every member of our Conference to support their ideas to create jobs, increase America’s energy supply, strengthen our national security and cut Washington spending.”

It is also possible that a Tea Party Republican allied with South Carolina Sen. Jim DeMint could seek a leadership position, potentially the fourth-ranking Republican Policy Committee chairmanship. Newly elected Tea Party members are not currently represented in the senate GOP leadership.