Over the past week or so, there have been several polls that suggest that perhaps GOP Sen. Rick Santorum is beginning to close the gap with Democratic state Treasurer Bob Casey, Jr.  

There have been 35 polls released in this contest and Santorum has trailed Casey in every one of them.   The incumbent has been within the margin of error in only one of these surveys (a Franklin & Marshall College poll in February of 2005), and has been behind by as many as 18 points.   Polls taken over the last six weeks or so do suggest that the gap has narrowed, although Santorum remains behind and outside the margin of error.

A Quinnipiac University poll taken in mid-June had Casey ahead of Santorum, 52 percent to 34 percent, but Quinnipiac's August survey had the race at 7 points, 51 percent for Casey to 44 percent for Santorum.

Strategic Vision, a Republican polling firm that is conducting surveys in this race for its own use, showed Casey leading Santorum by 9 points in both its May and June polls and by 10 points in its July survey.   In Strategic Vision's August 11-13 poll, the margin had dropped to 7 points, with Casey leading Santorum, 48 percent to 41 percent.  

In addition, a Muhlenberg College poll for the Allentown Morning Call (July 31-August 3 of 550 registered voters) also showed Casey with a 6-point advantage, 45 percent to 39 percent.  

The closure has given strategists of both parties some pause because such closure over a relatively short period of time is often the result of a major event.   There haven't been any such "forcing" events here.   However, there are a few factors that have combined to create some small movement in this race.

First, the Santorum campaign has aired significantly more television--much of it on cable--than Casey has.   Casey launches his television advertising tomorrow.   Santorum's ads have focused on immigration, Social Security, and his efforts to pass child safety legislation.   In another ad, Santorum goes as far as to poke fun at the vastly different ways the state's newspapers have portrayed him.

Second, Santorum's emphasis on immigration, an issue on which he opposes President Bush, appears to have some traction in some of the state's more rural areas.   A Washington Post story this week profiled the town of Hazleton, which recently enacted laws to penalize landlords for renting to illegal immigrants and employers for hiring them.   Hazleton's actions may be extreme, but there is evidence that other municipalities share its views.

Third, it is possible that Carl Romanelli, a Green Party candidate, will qualify for the ballot.   Democrats are pulling out all the stops to keep Romanelli off the ballot while the Green Party is working equally hard to keep him on.   The most recent polls have included Romanelli's name for the first time.   In the August Quinnipiac poll, he pulled 5 percent to 48 percent for Casey and 42 percent for Santorum in a three-way ballot test.   According to the Strategic Vision poll, Romanelli took 4 percent to 47 percent for Casey and 41 percent for Santorum.  

In recent elections, Green Party candidates have not had an impact in statewide races in Pennsylvania.   Since 2000, Ralph Nader scored the strongest performance, taking 2.1 percent in the presidential contest.   Democrats' efforts to keep Romanelli off the ballot would suggest that they believe that the race might be close enough to turn him into a spoiler.   And, it is not a stretch to see how Romanelli might do somewhat better than Nader, since there are still some liberal Democrats unhappy with Casey's pro-life and pro-gun stances.

Finally, it is likely that whatever ground Santorum has gained is simply a reflection of the natural closure of the race.   One reason that The Cook Political Report never gives an extremely endangered incumbent a rating worse than Toss Up is that incumbents have a tendency to come back in the final months of the campaign regardless of how far behind they've been.

In what certainly appears to be an effort to tamp down talk that Santorum is gaining on Casey, Democrats released a poll this week that showed Casey with an 11-point lead.   The Benenson Strategies Group survey (August 13-16 of 821 likely voters) for the Democratic Senatorial Campaign Committee had Casey ahead of Santorum, 51 percent to 37 percent.   In a three-way ballot test, Casey took 48 percent to 37 percent for Santorum and 3 percent for Romanelli.   It is interesting to note that Romanelli's 3 points came directly out of Casey; Santorum's level of support did not move.

If this race has moved, it's been in millimeters.   Santorum still has a ways to go to overtake Casey and the closer he gets, the steeper the hill he must climb.   Still, there is enough data to make this worth watching.   It is entirely possible that Casey's television advertising could break the race open, but if it doesn't, this will be a fight to the finish.  

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