The resignation came just a day after another Edwards blogger, , left her post at the campaign because of widespread criticism for similar blog posts.

The pair last week was roundly criticized by Bill Donohue, president of the Catholic League, and others for blog postings written before they joined the former North Carolina senator's campaign. Bill Donohue called on the Edwards campaign to fire the bloggers for their comments. Last week, Edwards said he was offended by the posting but did not fire the bloggers.

On her blog, McEwan said she was hired by the campaign as a part-time technical adviser, not a blogger.

"This was a decision I made, with the campaign's reluctant support, because my remaining the focus of sustained ideological attacks was inevitably making me a liability to the campaign, and making me increasingly uncomfortable with my and my family's level of exposure," McEwan wrote on her blog.

In addition to Edwards, several other presidential candidates including Sen. Hillary Clinton (D-N.Y.) and Sen. Barack Obama (D-Ill.) have turned to like blogs and social networking to help boost their appeal to voters.