WASHINGTON - Former Republican Lt. Gov. Steve Kirby says he will decide within the next week whether to challenge South Dakota Sen. Tim Johnson this November.

"I'm undecided but I am working feverishly on trying to come up with a decision in the next seven days," Kirby said Thursday.

South Dakota Republicans have been searching for GOP candidates to challenge Johnson this year. The Democrat's bid for a third term has attracted little attention as South Dakotans have focused on his recovery from a brain hemorrhage, and the election has been seen as Johnson's to lose.

Kirby is more well-known than other Republicans who already have announced, and he is a wealthy businessman who potentially could fund a Senate race. He says he is talking to people in South Dakota and in Washington, including some members of Congress and the White House, who are trying to recruit him.

"I'm talking to people all over the country to make sure I turn over every stone and know every little bit of information before I make the decision," he said. "It will be a family decision."

In the meantime, he already is talking like a candidate. Fiscal responsibility would be a cornerstone of his campaign, he said.

"I am concerned that we continue to spend money in Washington that we don't have," Kirby said. "Eventually that is going to have to be repaid."

Kirby ran for governor in 2002, coming in third in the GOP primary after he and then-Attorney General Mark Barnett attacked each other in a nasty, expensive campaign. The other contender, Mike Rounds, stayed above the fray, winning the primary and eventually the general election with 57 percent of the vote.

He was also on the losing end of the 1994 Republican gubernatorial primary, when Bill Janklow ousted GOP Gov. Walter Dale Miller. Kirby was Miller's lieutenant governor.

Former state Republican Party chairman Joel Rosenthal noted that Kirby has lost two races and said he lacks some broad appeal among Republicans. But that doesn't mean he couldn't have a strong candidacy now, Rosenthal said.

"I think Republicans could get excited about Steve Kirby this year," Rosenthal said.

Kirby "probably fits Washington's model right now," he added. "The national Republicans are looking for self-funders."

A candidate with personal wealth could help national Republicans who probably will spend much of their money on higher-priority Senate races.

While Johnson was considered vulnerable early on - he fended off a challenge from Republican John Thune by only 524 votes in 2002 - he became less so after a life-threatening brain hemorrhage in December 2006.

Johnson spent nine months out of the Senate recovering from the hemorrhage, and Republicans stayed quiet out of respect for his health.

Three Republicans - state Rep. Joel Dykstra, retired real estate agent Bert Tollefson and Sam Kephart, a self-employed businessman - eventually jumped into the race, but none are well-known or could match the $2.4 million Johnson had in the bank at the end of last year.

Rounds, seen as the biggest potential threat to Johnson, has shown little interest in challenging him.

So far, Republican candidates have said little about Johnson's health, keeping that issue out of the campaign. The senator now uses a wheelchair or a cane to get around, and his words are often slurred.

Kirby said Johnson's health has no place in the political process.

"It would not ever be mentioned as part of any campaign that I would run," Kirby said. "It's a personal medical matter for Sen. Johnson and I would respect that, and anyone who was part of my campaign would as well."

For now, Kirby also says he hasn't decided if he would fund his own campaign.

"At this point I have not linked any personal financial commitment to the decision," he said.

Johnson spokeswoman Julianne Fisher declined to comment on a Kirby run, saying "the senator is focused on being a senator."

"He's traveling around the state this week meeting with constituents and the campaign is something that will take care of itself in time," she said. "When the race heats up, we will take on any and all comers and we expect to win."