Three other incumbents are facing stiffer competition.
Paul Kanjorski, a 12-term congressman, is holding an early lead over Hazleton Mayor Lou Barletta in northeastern Pennsylvania.
In southwestern Pennsylvania, 17-term Democrat John Murtha holds an early lead over Republican William Russell.
In the state's northwest corner, seven-term Republican Rep. Phil English is trailing Democratic political newcomer Kathy Dahlkemper.
With 11 percent of precincts reporting, Dahlkemper leads with 57 percent of the vote.