(CNN) - New poll numbers suggest the Senate contests in Washington State and Pennsylvania are tightening up while the GOP is up big in the Senate race in Ohio.
A Muhlenberg College/Allentown Morning Call survey released Wednesday of likely voters in Pennsylvania indicates that Rep. Joe Sestak, the Democrat's nominee, holds a 44 to 41 percent advantage over former Rep. Pat Toomey, the Republican nominee, with 15 percent undecided. Sestak's two point margin is within the poll's sampling error.
In Muhlenberg's previous survey, conducted two weeks ago, Toomey led 46 to 39 percent. Most other recent polls also indicated Toomey with a single digit lead.
Earlier this year Sestak, a former admiral and two-term congressman from southeast Pennsylvania, came from behind in the polls to defeat Democrat Sen. Arlen Specter for their party's nomination. When Specter switched parties last year, he cited the difficulty in winning the Republican primary against Toomey as a factor. Besides his service in Congress, Toomey is also the former head of the Club for Growth, a limited-government and anti-tax organization, and he enjoys the support of many in the Tea Party movement.
In Washington State, a McClatchy/Marist poll of likely voters indicates that race between Democratic Sen. Patty Murray and Republican nominee Dino Rossi is deadlocked, with Murray holding a 48 to 47 percent margin over Rossi. Murray held a larger single digit advantage in most other recent polls.
Vice President Joe Biden teamed up with the three-term senator Wednesday in Washington State, and President Barack Obama Thursday joins Murray in the state. Rossi was the state's GOP gubernatorial nominee in 2004 and 2008.
While the Senate contests in Washington State and Pennsylvania appear to be all tied up, it's apparently a very different story in Ohio. A Quinnipiac University poll released Wednesday indicates that GOP Senate nominee Rob Portman holds a 55 to 34 percent lead over Lt. Gov. Lee Fisher, the Democrats' nominee. Portman's 21 point advantage is up slightly from a 19 point lead two weeks ago.
Portman is a former representative and a Bush administration budget director. The winner in November will succeed retiring Republican Sen. George Voinovich.
The Muhlenberg College poll was conducted October 9-16, with approximately 400 likely voters in Pennsylvania questioned by telephone. The survey's sampling error or likely voters is plus or minus five percentage points.
The McClatchy/Marist poll was conducted October 14-17, with 589 likely Washington State voters questioned by telephone. The survey's sampling error for likely voters is plus or minus four percentage points.
The Quinnipiac University poll was conducted October 12-17, with 1,188 likely voters in Ohio questioned by telephone. The survey's sampling error for likely voters is plus or minus 2.8 percentage points.
Follow Paul Steinhauser on Twitter: @PsteinhauserCNN