Even as most Americans said they did not believe Fox News employee Sarah Palin was in any way responsible for the recent mass shooting in Tucson, Arizona, the former Alaska governor's poll numbers have taken such a significant hit in recent months that they've finally reached the lowest point in her career as a national figure.

The woman considered to be the most popular Republican vying for the party's 2012 nomination was rated by respondents to a USA Today/Gallup poll published Tuesday.

The polling firm found that Palin's favorable rating has declined to just 38 percent, down from a high of 53 percent when she was first introduced on the national stage by Sen. John McCain (R-AZ) during the 2008 presidential campaign.

Another key metric, her unfavorable rating, has also eclipsed its prior high, hitting 53 percent in the latest poll, up from 28 percent since the presidential campaigns.

Palin saw a torrent of largely negative media coverage after Rep. Gabrielle Giffords (D-AZ) was shot in the head by a lone gunman outside a grocery store in Tucson.

The Fox News employee's critics latched on to a map of the United States she'd published on Facebook during the 2010 elections, showing 20 congressional districts with gun sights over them. She'd further encouraged supporters to "reload" and "take aim" at Democrats.

When the graphic was first published, amid a highly bitter and often fiction-laden Republican campaign against Democrats' health care reforms, Rep. Giffords criticized her for using firearm images and terminology in her public statements, predicting there would be "consequences."

Palin's response was met with a similarly poor reception, when she used the term "blood libel" to describe media coverage of her violent rhetoric following the shootings. "Blood libel" is an antisemitic term with a long history: it was most often used to justify lynching Jews, who were said to have killed children and used their blood in religious rituals.

Rep. Giffords happened to be Jewish: a fact likely not considered by Palin's speech writers when they chose the term. It was largely seen as a major PR blunder, and the Anti-Defamation League came out with a demand that she apologize. Instead, Palin defended her use of "blood libel" by offering a new and previously unheard of definition for the term.

Her flagging fortunes came at the same time an ABC News/Washington Post poll found that unpopularity ratings for the tea parties -- which were originally founded by supporters of Rep. Ron Paul (R-TX) but largely co-opted by mainline Republicans and corporate interests -- have also hit an all time high.

Fifty-two percent of the US public had an unfavorable view of "the political movement known as the Tea Party," the survey found, as opposed to only 35 percent who approved.

The shift may reflect a populace growing uncomfortable with the divisiveness of the tea party's designated leaders, such as former Alaska governor Sarah Palin, Fox News host Glenn Beck, and Minnesota Republican Michele Bachmann.

Obama, Boehner also up

Meanwhile, President Barack Obama, who's long been the target of what one former Bush administration speech writer called the "paranoid narratives" coming from so many of the tea parties' leaders, was on the rebound since the 2010 mid-term elections.

His favorable rating, according to Gallup, reached 53 percent, down from a high of 78 percent when he took office in January 2009. Similarly, Gallup's unfavorable rating for Obama showed a slight downward shift, hitting 45 percent in recent weeks, down two points since the mid-term elections.

House Minority Leader Nancy Pelosi (D-CA) also saw a recent improvement in her opinion metrics, though not by much. Her unfavorable rating remained high, at 54 percent, but her favoriability rating since retaining her leadership post after the mid-term elections has gone up, from 29 to 33 percent.

Perhaps the greatest beneficiary of Americans' changing opinions was House Speaker John Boehner, whose favorable rating hit 42 percent in Gallup's recent polling. That's up significantly from Nov. 2010, when it sat at 27 percent.

Similarly, his unfavorable rating dropped from 31 to 22 percent, with Gallup citing increasing favor among Independents and Democrats for the shift.