U.S. Sen. Arlen Specter continues to enjoy a commanding lead in his bid for a fifth term, the latest Pennsylvania Poll shows.

The Republican incumbent was the choice of 50 percent of the 800 likely voters interviewed Tuesday through Thursday, running far ahead of Democratic challenger Joe Hoeffel, at 32 percent.

Constitution Party candidate Jim Clymer had 7 percent, while 11 percent of respondents were undecided.

Specter's campaign team welcomed the poll results.

"This shows again that voters are responding to Sen. Specter's record of using his seniority to deliver for the state," said Christopher Nicholas, the Republican's campaign manager.

"It is also further evidence that Joe Hoeffel's far-left campaign, less than two weeks out, has not gained any traction," Nicholas said.

Hoeffel's campaign manager, Kristin Carvell, played down the significance of the poll.

"The only poll that matters is the one on Election Day," she said. "[Pennsylvanians] are ready for a change in Washington and they're going to elect Joe Hoeffel."

Specter, as the first four-term senator in the state's history, began the race with a huge advantage in name recognition. Relatively few people knew Hoeffel outside the Philadelphia area, where he has served as a congressman for three terms.

The Democrat insisted throughout the summer that his poll numbers would improve once his television commercials hit the airwaves.

As it turns out, Hoeffel's numbers have barely budged, even after five weeks of television spots. A Pennsylvania Poll conducted Sept. 27-28 had Specter leading 53 percent to 31 percent, a gap only four points larger than the senator's current advantage.

In both polls, 18 percent of likely voters said they didn't recognize Hoeffel's name. Specter's name, in contrast, was recognized by all but 2 percent of respondents in the September poll and 1 percent in October's.

A shortage of campaign funds has prevented Hoeffel from saturating the airwaves with the number of commercials needed to tighten the race.

Both candidates spent roughly $2 million between June 30 and Sept. 30, according to their campaign finance reports. But Specter entered October with $3.29 million in cash on hand, to $450,000 for Hoeffel.

In his commercials and on the stump, Hoeffel has tried to tie Specter to President Bush, continually reminding voters that the senator has voted with the administration 89 percent of the time.

But the poll shows that Specter's centrist reputation remains intact -- despite his having enlisted the help of Bush and U.S. Sen. Rick Santorum, conservatives both, to survive a tough battle in this spring's Republican primary against U.S. Rep. Pat Toomey of Allentown.

Specter is cutting into Hoeffel's base, picking up the support of 33 percent of likely Democratic voters in the Pennsylvania Poll, to the challenger's 54 percent.

It helps the senator that he hails from the Democratic stronghold of Philadelphia, where he served two terms as district attorney.

In Philadelphia, Specter is leading Hoeffel 46 percent to 37 percent, according to the poll.

In Allegheny County, another Democratic bastion, Hoeffel held a 46 percent to 39 percent lead.

Specter's chief concern has been that Clymer will siphon away enough Republican votes to give Hoeffel a chance of winning.

But the Pennsylvania Poll indicates that Clymer, as the race's lone anti-abortion candidate, is not attracting enough support to be a spoiler.

While the Constitution Party candidate was the pick of 11 percent of likely Republican voters, Specter still polled at 67 percent within his own party, to 8 percent for Hoeffel.

The Pennsylvania Poll results could have an impact on the campaign down the home stretch.

Hoeffel wanted a strong showing in the latest round of surveys to convince the Democratic Senatorial Campaign Committee and other donors that he merits additional contributions.

But the Pennsylvania Poll results are similar to those from the most recent Quinnipiac University poll, which showed Specter leading 51 percent to 36 percent, with 6 percent for Clymer.

Conducted for the Pittsburgh Post-Gazette by Mason-Dixon Polling and Research of Washington, D.C., the Pennsylvania Poll has a statistical margin of error of plus or minus 3.5 percent.