Oregon's Gordon Smith has become the fourth Republican Senator to disavow John McCain's robocalls linking Barack Obama to Bill Ayers.

In a statement to the Huffington Post, Smith for Senate press secretary Lindsay Gilbride said:
"They [the Ayers calls] are not taking place in Oregon and Senator Smith does not condone these sort of calls. Negative robocalls are not appropriate and have no place in campaigns."

The McCain campaign's tactics have come under heavy fire in recent days, including from Republican Senators Norm Coleman, Olympia Snowe and Susan Collins. Vice presidential nominee Sarah Palin even acknowledged that voters were becoming "irritated" by the onslaught of campaign calls. Meanwhile, McCain himself was forced to defend the tactic in a recent interview, saying "that robocall is exactly accurate."

Even as the campaign tactic has courted disdain from fellow Republicans, it's not clear that the robo calls have helped McCain's campaign. A CNN poll released this week showed that most Americans now believe that McCain's attacks against Obama are unfair.

It's not hard to figure why Smith's camp made the move to officially distance itself from the McCain robocalls: Obama is on pace to handily carry the state on November 4.