The Pew Charitable Trusts

Pennsylvania and Ohio are the sixth- and seventh- most populated states in the nation, according to the U.S. Census, so the outcome of their gubernatorial elections will be important nationally, particularly as redistricting and the 2012 presidential campaign season approach. Up until recently, however, both races were seen as lopsided affairs, with Republican candidates easily out-polling the Democrats.

That may be changing.

In Pennsylvania, where Republican Attorney General Tom Corbett has consistently held a double-digit advantage over Democrat Dan Onorato, a new poll by Franklin & Marshall College may make critics of Onorato "hold their tongue," as The Patriot-News of Harrisburg put it . The poll has Corbett leading Onorato by just three percentage points among registered adults and four points among likely voters, and comes after a wave of television advertising on the part of Onorato. A separate poll, the Susquehanna Polling & Research survey, found the race narrowing in Onorato's favor, too. The winner will replace Democrat Ed Rendell, who cannot run again because of term limits.

In Ohio, incumbent Democrat Ted Strickland also appears to be making up ground against Republican challenger John Kasich, a former U.S. congressman. The Columbus Dispatch breaks down a series of polls from various outlets that show the race within a few percentage points, and the national attention that is being focused on Ohio certainly suggests a battle in November. The Christian Science Monitor recently called it " the most important governor's race " of the 37 taking place this year, and both candidates have called on big-name supporters. Vice President Joe Biden campaigned with Strickland this month, while Kasich teamed up with New Jersey Governor Chris Christie, a rising Republican star. Like Pennsylvania, Ohio went Democratic in the last presidential election, and the GOP is hoping to establish a foothold ahead of 2012.