Republican Tom Smith is gaining ground on incumbent U.S. Sen. Bob Casey, according to results of two new polls.
Mr. Smith has been chipping away at Mr. Casey's lead in a race for a seat widely considered to have been safely in Democratic hands.
If poll numbers continue in that direction, observers say Mr. Smith -- whose campaign is largely self-financed -- could end up with more help from the Republican National Committee, which is seeking to regain control of the Senate.
A spokesman for the Republican National Committee could not immediately be reached.
Mr. Casey leads 49 to 43 percent among likely voters, according to the telephone poll conducted over the last week by Quinnipiac, The New York Times and CBS News. The margin of error is plus or minus 2.9 percent.
The poll "is further confirmation that Tom Smith's pro-jobs message is resonating with Pennsylvania voters as Smith has clearly captured the momentum," said Smith campaign manager Jim Conroy. "Voters are rejecting Bob Casey's misleading negative attacks in favor of Tom's positive vision for the future and detailed plan to grow the economy and create jobs."
The Casey campaign says Mr. Smith is the one who has gone negative.
"He's continuing to put his personal fortune into negative attack ads to cover up his Tea Party record," said Casey campaign spokesman Larry Smar.
Franklin & Marshall College conducted a poll of registered voters during the same time period as Quinnipiac's survey. Its results show Mr. Casey leading 48-38 among registered voters. Fourteen percent said they were undecided.
A month ago, a series of polls by Quinnipiac, The Philadelphia Inquirer and The Morning Call of Allentown had Mr. Casey leading by 18 and 19 percentage points among likely voters. Several polls conducted during the last two weeks suggest the gap is closing.
Mr. Smar said Democrats remain confident Mr. Casey will hold his lead and that the campaign doesn't plan to change its strategy based on recent poll results.
Franklin & Marshall pollster G. Terry Madonna said it's too soon to say whether Mr. Smith is within striking distance.
"We need to see a big trend line" to draw that conclusion, he said.
It isn't surprising that Mr. Casey's lead is shrinking, he said.
During the earliest polls, some voters had never heard of Mr. Smith, Mr. Madonna said.
"Do I think it's a tighter race? Sure. Do I think there's room for Smith to grow? The answer is yes," he said. "The question is whether there is room enough for him to grow enough and that's what we don't know. It seems like an uphill climb, and that's why everybody has the race listed as likely Democratic or safely Democratic."
Mr. Casey, of Scranton, is seeking his second term in the Senate. He previously served as Pennsylvania's treasurer and auditor general.
Mr. Smith is a grain farmer and a former coal company owner. He lives in Shelocta, a rural community 40 miles north of Pittsburgh.
Washington Bureau Chief Tracie Mauriello: firstname.lastname@example.org or 703-996-9292.