Five candidates are seeking the Democratic nomination for U.S. Senate and the right to challenge Saxby Chambliss, the Republican incumbent, in the fall. But only one —- former state Rep. Jim Martin —- has the experience, the character and the intellect demanded for the role.

Rand Knight, an environmental engineer and software salesman, has the intellect and character but has never held or sought public office. A seat in the U.S. Senate would be too big a step, too soon. Dale Cardwell, a former TV reporter, touts himself as an alternative to "business as usual" but has done nothing to establish himself as more than a protest candidate. Camping out on a tower in the dead of winter may draw publicity, but it is not the act of a potential U.S. senator. Josh Lanier, a retired businessman and consultant, is not running an aggressive campaign.

The remaining candidate, DeKalb County CEO Vernon Jones, is a special case. He is a man of large talents and large flaws, but those flaws of temperament, character and judgment are so large as to disqualify him from consideration for higher office.

During his controversial tenure as county executive, Jones has twice been accused of physical confrontations with women, with one case ending only after Jones wrote two apologies to a fellow county official "for the language I used and/or for my conduct toward you, which I now realize was inappropriate and which I now acknowledge has no place in the conduct of our personal and professional affairs."

In a third case, Jones was accused of rape. His defense —- that sexual acts between himself and two women had been consensual, not forced —- does not engender confidence in a senatorial candidate. (The charge was later dropped at the request of the alleged victim, who continued to stick by her version of events.)

Voters in a Democratic primary might also question the wisdom of nominating a man who has acknowledged voting for President Bush in 2000 and again in 2004. Having Jones at the top of the Democratic ticket statewide would not just harm the hopes of candidates for lesser office, it would taint the Georgia campaign of presidential nominee Barack Obama as well.

Fortunately, Martin offers an attractive alternative. A Vietnam veteran, he has earned deep bipartisan respect through his service in the state Legislature and as commissioner of the state Department of Human Resources under Gov. Roy Barnes, a Democrat, and Gov. Sonny Perdue, a Republican.

Martin also stresses the importance of being an independent voice for Georgia in the Senate regardless of who is elected president, drawing a contrast to the blind allegiance he claims Chambliss has given to Bush. His nomination would bring credit both to his party and to his state.

—- Jay Bookman, for the editorial board (jbookman@ajc.com)