A new survey shows Gov. Tom Corbett (R) trailing Democratic challenger Tom Wolf, 49 percent to 42 percent, the tightest margin between the two candidates in any public poll so far.

The poll, released Friday by the news website Keystone Report, was conducted by Magellan Strategies, a GOP-leaning research firm based in Baton Rouge, La. It suggests a much closer race than other recent surveys, and is in line with what Pennsylvania Republicans say they have been seeing in private polls.

A poll conducted between Sept. 30 and Oct. 5 by Quinnipiac University, for instance, found that Wolf was leading by 17 percentage points.

The Real Clear Politics poll aggregator puts Wolf's lead at an average of 11 percentage points, with slightly more than two weeks to go in the campaign.

In a memo released with its poll, Magellan said that Corbett's improved standing with Republicans over the course of three polls it has conducted for Keystone Report is responsible for his somewhat closing the gap with Wolf.

In July, Magellan found he had the support of 64 percent of GOP likely voters. The latest survey found Corbett backed by 73 percent of his fellow Republicans. It also noted a slight uptick in negative views of Wolf.

The pollster said the biggest difference between its finding and those of other recent polls is that the weighting of its responses assumes a lower relative turnout of Democrats compared to Republicans. Magellan said the assumption fits the state's historical turnout patterns in non-presidential election years.

The Magellan poll, an automated phone survey with a margin of error of plus or minus 2.9 percentage points, was conducted Oct. 13-14, and was based on 1,131 responses from voters who indicated they were likely to go to the polls Nov. 4.