JEFFERSON CITY — One candidate is in, another is out, and the timer now is ticking for four other politicians to declare their intentions in the 2012 Republican primary to challenge Democratic Missouri Sen. Claire McCaskill.
The field of potential Republican candidates recently grew by subtraction. When former Sen. Jim Talent — whom McCaskill defeated in 2006 — declared he will not seek a rematch, others who had deferred to a Talent candidacy began to take a more serious look at the Senate race.
Missouri's Senate race, as usual, is likely to be one of the most closely contested in the nation. McCaskill has cut a high profile for a freshman. She's backed President Barack Obama's health care and stimulus laws yet broken from Democratic Senate leaders by attacking earmarks and led investigations in government contracting.
So far, McCaskill has just one announced challenger — former Missouri Treasurer Sarah Steelman, whose Dec. 1 entry was one of the earliest nationally for a 2012 campaign.
Other Republicans looking at Missouri's Senate race include U.S. Rep. Sam Graves of northwest Missouri, U.S. Rep. Jo Ann Emerson of southeast Missouri, former Missouri Republican Party Chairwoman Ann Wagner of St. Louis and Ed Martin, a St. Louis attorney who ran unsuccessfully for Congress last year.
It's unlikely all four will run. The next decision likely will come from Graves, who plans an announcement before the end of this week.
Graves may have the most name recognition among the remaining fence-sitters. Through a decade of campaigns for the 6th Congressional District, he has aired ads across the Kansas City television market, which extends well beyond his own district.
Kansas City has been a stronghold for McCaskill, who was a state lawmaker and prosecutor there. But Graves could cut into McCaskill's geographical base. He also has rural roots, which serves Missouri politicians well, and he voted against federal bailout and stimulus bills — positions that played well in the 2010 elections.
Graves recently was named chairman of the House Small Business Committee, which he said marks the first time anyone from the 6th District has led a House committee. Graves told The Associated Press that he might have to resign from the chairmanship if he were to run for the Senate, because both would demand a lot time.
"I've got a lot of stuff I want to do as chairman of the Small Business Committee," Graves said.
But "Claire McCaskill's extremely vulnerable. She's got a lot of votes out there that just do not sit well with the state of Missouri," he added. "Opportunities don't come around very often when you're talking about U.S. Senate."
Emerson, like Graves, has a natural base from representing southeast Missouri's 8th Congressional District since 1996. She convincingly won re-election last year against her most active Democratic challenger in years. She has built some name identification in an important Republican area by airing congressional campaign ads in the Springfield market. But she has little exposure in Missouri's biggest media markets.
Emerson's chief of staff said she did not want to discuss her Senate campaign deliberations.
Wagner told the AP that she would defer to both Graves and Emerson before entering the Senate race herself.
Wagner lost a race just a couple of weeks ago for the chairmanship of the Republican National Committee. She's a former ambassador to Luxembourg, former chairwoman of the state Republican Party, former co-chairwoman of the RNC and last year was chairwoman of Roy Blunt's winning senatorial campaign.
Wagner would bring an extensive Republican network to a Senate bid, which could aid her in grass-roots organizing in fundraising from both in-state and out-of-state sources. Although she's advised numerous other candidates and is adept at stump speeches, Wagner has never run for state or federal office and would be starting virtually from scratch in building name recognition among the general public.
"You don't do something like this unless you think you can make a difference and there needs to be a change," Wagner said. "I certainly feel a change is necessary, and I may be the person to be able to shine a bright light on what the concerns are with Claire McCaskill."
Wagner said she hopes to make a Senate decision by the Republicans' annual Lincoln Days conference Feb. 25-27 in Springfield.
Martin set no timetable for his decision. He's been considering the race for several months with a growing interest. This past week, Martin highlighted a Facebook posting from conservative activist Phyllis Schlafly and a statement from former Missouri Veterans Commission Chairman Joe Frank, both encouraging him to run for Senate.
"Over the last month or so, it has become less a factor for me who (else) is running and more a factor of how could I — how could my campaign — do it," Martin told the AP.
Martin, who was chief of staff to former Gov. Matt Blunt, made a name for himself last year when he put up strong fundraising numbers, drew support from tea party activists with a conservative message, made effective use of social media and nearly upset Democratic U.S. Rep. Russ Carnahan in a traditionally strong Democratic district in the St. Louis area. He earned a reputation as a relentless campaigner.
McCaskill also has a reputation as an effective campaigner over a political career that will have spanned 30 years when she is next on the ballot. She's one of Missouri's most outspoken politicians. But she's trying to keep silent about her potential challengers.
"I have feeling there will be plenty of people in Missouri that will be handicapping the Republican primary for many months to come," McCaskill said last week. "But I don't think there's really anything for me to be gained by commenting about it, and I don't intend to."
David A. Lieb has covered state government and politics for The Associated Press since 1995.