(CNN) - A majority of Americans think Sarah Palin is stepping down as Alaska's governor for political reasons, according to a new national poll, with a majority of Republicans now saying that they do not believe that Palin would be an effective president.
Only 33 percent of Republicans questioned in a CBS News survey released Monday night say that Palin would have the ability to serve effectively as president. Last fall, 71 percent of registered Republicans felt that way.
"It's unclear whether the change in Republicans' view of Palin is the result of her decision to step down as governor, or whether the GOP rank-and-file felt they had to defend their party's vice-presidential nominee during the campaign but don't feel the same tug of party loyalty today," said CNN Polling Director Keating Holland. "Either way, this is bad news for Palin, whose first task in 2012, if she runs for the White House, will be to convince Republican primary voters to support her."
Fifty-two percent of all respondents in the CBS survey said that Palin is resigning because she thinks its better for her political career, with one in four agreeing with Palin's comments that her resignation would benefit Alaska. Most Democrats and independents feel Palin's resignation is politically motivated, while Republicans appear divided, with 36 percent indicating the move is to advance her political career and 31 percent agreeing with Palin's explanation.
"That's another indication that Palin may face a skeptical GOP primary audience if she chooses to run for president," Holland says.
Americans appear divided on whether Palin will run for the White House in 2012, with 43 percent feeling Palin will make a bid for the presidency, 39 percent indicating she will not run, and 18 percent unsure.
Palin has been critical of her coverage in the national media. Nearly half of those questioned, 46 percent, say the media's been harder on Palin compared to other political figures, with only seven percent saying the media's been easier on her than other politicians. Forty-four percent say her treatment's been about the same.
The CBS News poll was conducted July 9-12, with 944 adult Americans questioned by telephone. The survey's sampling error is plus or minus three percentage points.
CNN Deputy Political Director Paul Steinhauser contributed to this report