The primary ballots are set in the must-watch race to succeed retiring Sen. James Webb (D-Va.).

On the Democratic side, former governor Timothy M. Kaine will be unopposed in the June 12 primary. Two potential primary challengers — Courtney Lynch and Julien Modica — recently dropped their prospective bids and endorsed Kaine.

In the Republican field, former governor and senator George Allen is considered the clear favorite to win the party’s nomination, but he will have to beat out three other candidates: Bishop Earl Jackson, Del. Bob Marshall (Prince William) and former Virginia Tea Party Patriots head Jamie Radtke.

Virginia Beach lawyer David McCormick also collected signatures to get on the Republican primary ballot. State officials said he was disqualified because he did not submit a check or declaration of candidacy, but his campaign issued a statement saying he decided not to submit signatures because he “could not achieve the threshold of 10,000 verified signatures” required by law.

The four Republicans on the ballot are scheduled to hold three debates before the primary — one apiece in Roanoke, Northern Virginia and the Hampton Roads region.

Allen has a huge advantage in fundraising and name identification over the other candidates.