It has been a tough couple of days for former Alaska governor and Fox News commentator Sarah Palin.

A new ABC News/Washington Post poll, released Wednesday, found that Ms. Palin’s favorability ratings among Republicans and Republican-leaning independents have dropped to a new low. Fifty-eight percent of those voters still view her favorably – not exactly shabby, by most standards. But compared with the 88 percent favorable rating she enjoyed right after Sen. John McCain picked her as his running mate in 2008 – and even the 70 percent positive rating she enjoyed as recently as October – Palin is definitely on a downward slide.

Even more troubling for Palin, especially if she harbors presidential ambitions, is that her negative ratings among Republicans are higher than those for other possible GOP presidential contenders. Thirty-seven percent of Republicans and Republican-leaners see Palin unfavorably, the ABC News survey said. That exceeds former House Speaker Newt Gingrich’s unfavorable ratings by 11 percentage points, former Massachusetts Gov. Mitt Romney’s by 16 points, and former Arkansas Gov. Mike Huckabee’s by 19 points.

Support among Republicans is especially crucial for Palin given her standing with the general public. An ABC News/Post poll in December found that 59 percent of all likely voters would not consider voting for her for president.

“The results indicate continued challenges for Palin in public opinion,” Gary Langer wrote on the ABC News blog The Numbers. Mr. Langer provides public opinion polling and analysis to ABC News.

The poll slippage comes at a time when Palin's fellow conservatives are taking political pot shots at her. On Monday, former New Hampshire Sen. Judd Gregg wrote in The Hill newspaper that a presidential primary season in which there is no clear front-runner could help Palin. He added, “Although she is not viewed by most as strong enough to win, she is viewed by many as a person worth voting for to make a statement.”

In addition, several well-known conservatives criticized Palin in an article published Monday on the website Politico. Weekly Standard magazine writer Matt Labash told the website that Palin is "becoming Al Sharpton, Alaska edition" due to her "appeals to victimhood and group grievance." The same article quoted veteran conservative columnist George Will on Palin’s potential effect on an idea-driven conservative movement. Could the GOP remain the party of ideas if Palin were the presidential nominee? “The answer is emphatically no,” Mr. Will told Politico.