Republican Michele Bachmann's presidential bid is teetering under a challenge from Texas Governor Rick Perry that has created tension within her team and clashes with advisers over fundraising and strategy.

Bachmann's top two advisers moved aside this week in a rift worsened by Perry taking over her role as the leading conservative in the Republican nomination race.

Sources close to the campaign told Reuters that Bachmann blamed veteran campaigner Ed Rollins and his deputy, David Polyansky, for not letting her make key decisions and for staging over-slick campaign events that do not fit into her folksy style that appeals to Tea Party conservatives.

There has been lots of management of Michele. They are keeping her hidden, said a source close to the campaign. They are managing her to the nth degree. They are afraid she's going to mess it up.

A second Republican source close to the campaign said Bachmann's advisors insisted she focus on winning February's caucuses in Iowa, where she has a lot of support from conservatives. But Bachmann wanted a stronger national strategy, including visits to the key state of Florida.

The Bachmann campaign's trouble is rooted in the rise of Perry, who has become the Republican front-runner less than a month since joining the race. The two are fighting for the same conservative voters to win the Republican nomination and take on Democratic President Barack Obama next year.

This probably has much less to do with Michele Bachmann's personnel practices than it does than Rick Perry's poll numbers, said Dan Schnur, who worked on John McCain's 2000 campaign and now teaches politics at the University of Southern California.

LOST MOMENTUM

Bachmann was riding high a month ago when she won the Ames straw poll in Iowa, a key early gauge of Republican candidates' strength.

But Perry's entry -- announced the same day as Bachmann's Ames victory -- has dropped her from second to at best third place in polls of Republicans. Former Massachusetts Governor Mitt Romney is now in second place.

Bachmann was muted on Wednesday night at a debate of Republican candidates in California that was dominated by sparring between Romney and Perry. She offered only mild criticism of her main two rivals, who vowed to scrap Obama's healthcare reform with executive orders.

With all due respect to the governors, issuing an executive order will not overturn this massive law, Bachmann said. This will take a very strong, bold leader in the presidency who will lead that effort.

Perry is a threat to Bachmann's fundraising and sources close to her campaign said funds may be running low.

Bachmann relies on campaign money from small donors, many of them Tea Party activists. That strategy made the Minnesota congresswoman the top fundraiser in the House of Representatives last year. But to take her campaign to the next level, Bachmann needs to find major donors who pledge to collect $50,000 or more, known as bundlers, experts say.

It's quite possible one of the reasons for the shakeup is they have overspent ... Fundraising numbers may not have been close to the mark, said Larry Jacobs, a University of Minnesota politics professor.

A Republican source close to the campaign said Bachmann did not want to make phone calls to potential big campaign donors, anther source of friction with her top advisers.

DIFFERENCES ON CHASING DONORS

First was a difference in strategy -- where to spend her time after Iowa -- and the other was money. She didn't want to make the calls to big donors, the source said.

A third source close to the campaign said Bachmann and Rollins, a key figure in Ronald Reagan's winning 1984 campaign and Mike Huckabee's unsuccessful 2008 campaign, had disagreements on logistical issues, such as which backdrop to use for campaign events.

Bachmann had a difficult time resisting day-to-day involvement, said the source, who spoke on condition of anonymity so he could talk freely.

When the change was announced Monday, the Bachmann camp said Rollins would continue in a senior advisory position. Bachmann spokeswoman Alice Stewart said Rollins, 68, was cutting back because he needed a less physically demanding position. She said the shakeup would not change Bachmann's campaign strategy.

Why should we change strategy? There was only one contest and we won it, Stewart said, referring to the Iowa straw poll. We are not changing strategy in any way, shape or form. This was part of a planned shift after the straw poll.

Ryan Rhodes, an Iowa Tea Party leader, said Bachmann's people should let her interact more with voters.

When Michele is Michele one-on-one she is as good as it gets, Rhodes said. It's unwise to hold her back.