Alaska Governor Sarah Palin plans to resign this month and will not run for re-election as governor.
Ms Palin was the surprise choice as running mate for the Republican presidential candidate John McCain in last year's election. She ignited conservatives with her social views but turned off other voters who believed she was unprepared for the White House.
There has been speculation that she will seek to be the Republican Party's presidential candidate in 2012.
Ms Palin told a news conference she would transfer authority to Lieutenant Governor Sean Parnell and would not seek re-election.
She said she did not want to waste time on "political blood sport" and cited public criticism of her actions and her family since the 2008 campaign.
Ms Palin was cleared in November of wrongdoing in an abuse-of-power investigation into the firing of the state's public safety commissioner.