Voters also went to the polls for party primary elections in two other states. In Arkansas, Sen. Tim Hutchinson easily captured the Republican nod for his re-election bid, while in Oregon, the two main parties chose nominees for the November race to replace outgoing Democratic Gov. John Kitzhaber.
But the main drama was the gubernatorial race in Pennsylvania, where Rendell led state Auditor General Robert Casey 56 percent to 44 percent with 92 percent of the votes counted, after a wave of heavy voter turnout in Philadelphia and its suburbs.
Tuesday's poll capped a bitter gubernatorial contest that showed all the hallmarks of a full-blown general election campaign, including more than 30,000 television advertisements and $30 million in combined spending.
Rendell, 58, a Jewish liberal who favors abortion rights and gun control, ran mainly on his record as the mayor who pulled the fifth-largest U.S. city from the brink of financial insolvency in the 1990s.
Casey, 42, a socially conservative Roman Catholic, had the backing of the state Democratic Party hierarchy, organized labor, the National Rifle Association and abortion opponents. He owed much of his statewide name-recognition to his father, the late Gov. Robert Casey, whose own widespread popularity created a class of state voters called "Casey Democrats."
"Last February, when I started out on this campaign, nobody thought I had a chance to win because I was the Philadelphia candidate," Rendell, a former chairman of the Democratic National Committee, told scores of cheering fans.
"The experts said no Philadelphian could ever be elected governor of this state. But the experts, as they often do, underrated the people of Pennsylvania," he said.
The race took on national interest because there was no incumbent. Gov. Mark Schweiker, elevated to the position when two-term Republican Tom Ridge became U.S. homeland security director last November, chose not to enter the race.
Party insiders now believe Rendell has a good shot at delivering the governor's mansion back into the hands of Democrats after nearly eight years of Republican rule.
Standing in the way will be Republican Mike Fisher, the state attorney general, who had no primary opposition.
Pennsylvania also was the setting for a rare primary election battle between Democratic incumbents in the 12th Congressional District, where Rep. John "Jack" Murtha defeated Rep. Frank Mascara by an unofficial 66 percent to 34 percent.
Mascara, 72, entered the contest rather than face Republican state Sen. Tim Murphy in a reapportioned 18th Congressional District with a large Republican voter base.
Murtha, 69, of Johnstown, has been in the U.S. House of Representatives since 1974 and ranks as the No. 2 Democrat on the Appropriations Committee and the lead Democrat on the panel's Pentagon budget subcommittee.
Mascara was elected to Congress in 1995 after more than 22 years as a politician in Washington County, where he served as controller and commissioner.
In the Arkansas U.S. Senate Republican primary, Hutchinson had 80 percent of the vote against state Rep. Jim Bob Duggar, 36, with about half of precincts reporting. Duggar, a Christian conservative, challenged Hutchinson's long-standing message of family values amid the senator's divorce and remarriage to a former aide.
"Voters are willing to forgive and support," Hutchinson said late on Tuesday night when his victory was obvious. "The people have looked at my record of service and decided that was most important to them."
Republican Gov. Mike Huckabee and Democratic state treasurer Jimmie Lou Fisher cruised toward easy primary victories in their parties' gubernatorial primaries.
In Arkansas House races, former Rep. Jay Dickey had 80 percent of the vote over David Stearns in the 4th District Republican primary, winning the right to face Democratic Rep. Mike Ross in November. Ross beat Dickey, who had served four terms, by just 3,778 votes in 2000.
In the 2nd District, Democratic Rep. Vic Snyder had about 70 percent of the vote against Jim Baker of Conway, a former agriculture official in the Clinton administration. No Republicans are seeking the seat.
In Oregon's gubernatorial race, both parties had three-way contests for nominations to replace a term-limited Gov. Kitzhaber.
Democrat Ted Kulongoski, a 61-year-old former Oregon Supreme Court Justice and Attorney General will face off against Republican Kevin Mannix, a 52-year-old former state legislator for the Oregon governor's job.
Kulongoski garnered 49 percent of the vote or 130,932 votes with 83 percent of the all mail ballots tallied. In a tight three-way race for the Republican nomination, Mannix got 34 percent or 85,105 votes. With 83 percent of the votes tallied, his rivals each grabbed 30 percent.
Republican Sen. Gordon Smith had no primary opponent. He will face Democratic Secretary of State Bill Bradbury in November. Bradbury got 87 percent of the votes in his primary contest.
Voter turnout was hovering around 40 percent. Oregon is the only state that conducts all its elections by mail.
By David Morgan