Updated

Alabama Gov. Bob Riley easily beat back a GOP primary challenge from Ten Commandments judge Roy Moore on Tuesday, while Democratic former Gov. Don Siegelman trailed in his comeback fight against the state's first female lieutenant governor.

As eight states held primaries, New Jersey Republicans chose Tom Kean Jr., the son of a popular former governor, to challenge Democratic Sen. Robert Menendez in the fall. Also in Alabama, voters passed a ban on gay marriage by a 4-to-1 margin.

Iowa, California, Mississippi, Montana, New Mexico and South Dakota also held primaries, as many states reported low turnout.

The biggest race was the special election in Southern California to fill the House seat of imprisoned former Rep. Randy "Duke" Cunningham, with the political world hoping for clues to the public mood ahead of this fall's midterm elections.

Money and attention from around the country poured into the San Diego-area election, with the Democrats seeing a rich opportunity to capture a solidly Republican district. Cunningham, a Republican, was sent to prison for eight years for taking bribes on a scale unparalleled in the history of Congress.

In New Jersey, Kean — who critics said needed a convincing win to be a real challenger in the fall — easily defeated a more conservative candidate, winning three of every four votes. Menendez, appointed to his seat after former Sen. Jon Corzine became governor, beat a little-known challenger.

In the weeks leading up to Alabama's gubernatorial primary, polls showed Riley with a growing lead on Moore, the former state chief justice who became a hero to the religious right in 2003 when he was ousted over his refusal to remove the Commandments monument from the state judicial building.

With a third of precincts reporting, Riley led with 110,333 votes, or 66 percent, to Moore's 60,860 votes, or 36 percent. Among the Democrats, Lt. Gov. Lucy Baxley was ahead with 107,513 votes, or 61 percent, against Siegelman with 61,013 votes, or 35 percent. Siegelman spent Election Day standing trial on corruption charges stemming from his single term as governor.

Another Washington corruption case figured in Montana's primary, where GOP Sen. Conrad Burns sought the nomination for a fourth term. After his ties to disgraced lobbyist Jack Abramoff became known, Burns saw his popularity fall, and Democrats John Morrison, state auditor, and state Senate President Jon Tester jumped into the race.

California Gov. Arnold Schwarzenegger faced no major competition for the GOP nomination, while state Treasurer Phil Angelides and Controller Steve Westly fought a close and nasty contest for the Democratic nomination that left many voters dismayed.

In Iowa, the retirement of Democratic Gov. Tom Vilsack set off a scramble for the Democratic nomination, with early returns showing a very tight race. Republican Rep. Jim Nussle had no primary competition.

But California's special election drew particular attention, largely because polls showed Democrat Francine Busby with significant support against Republican former Rep. Brian Bilbray.

With national polls showing deep dissatisfaction with Congress, President Bush and the war in Iraq, Democrats hoped to score a victory and build momentum for the fall midterm elections.

Among the House incumbents facing primary challenges Tuesday were GOP Rep. Richard Pombo and hawkish Democratic Rep. Jane Harman, both of California.

A few races brought back some familiar names:

— Jerry Brown — the former California governor, presidential candidate and current Oakland mayor — sought the Democratic nomination for attorney general.

— Chuck Espy, a state lawmaker and nephew of Mike Espy, Mississippi's first black congressman since Reconstruction, lost his primary challenge to Democratic Rep. Bennie Thompson, as expected.

George C. Wallace Jr., son of the former Alabama governor, was trailing in the GOP primary for lieutenant governor to Luther Strange, a Birmingham attorney.

— Hollywood director Rob Reiner was the leading backer of a measure in California to create a $2.4 billion universal preschool program.