Virginia's Republican Senate race is the main event in Tuesday's primaries The main event in the primary is the Republican Senate contest, where three candidates are challenging front-runner George Allen, a former governor and senator who far surpasses them in fundraising and name recognition. The contentious and expensive race to succeed Sen. James Webb (D), who is retiring, is expected to help determine the Senate's balance of power next year. Allen's rivals - Chesapeake minister E.W. Jackson, Del. Robert G. Marshall (Prince William) and tea party activist Jamie Radtke - have spent months running to his right and criticizing him for failing to challenge the status quo. But Allen has set his sights on Kaine, focusing on his terms as governor and Democratic National Committee chairman for President Obama. Allen has been careful to avoid gaffes like those that contributed to his reelection loss in 2006, mostly speaking generally about the need for new energy sources, smaller government and less regulation. He has not answered specific questions on pay equity legislation, a plan by Rep. Paul Ryan (R-Wis.) to overhaul entitlements and whether he would support requiring women to undergo ultrasounds before abortions. "Smart money" on Allen Stephen Farnsworth, a political science professor at the University of Mary Washington, said it is rare for someone with the national recognition of Allen, who has been in Virginia politics for more than two decades, to be defeated in a primary. "To say the smart money is on George Allen is one of the biggest understatements of the week,"" he said. A Washington Post poll last month showed Allen getting 62 percent of the vote among likely GOP primary voters. Marshall was next with 12 percent, ahead of Radtke at 5 percent and Jackson at 3 percent. The four Republican candidates agree on many issues, all backing the Defense of Marriage Act, a repeal of the federal health care law, and smart spending on the military. They took part in three debates, but all took place on days when Virginians were unlikely to pay attention - over Memorial Day weekend, for instance. Only one was televised. Bob Holsworth, a former professor who moderated the final debate, said it has been difficult for the others to call attention to themselves, because there is more than one opponent. "There's no requirement that [Allen] has to engage them,"' Holsworth said. "It's very difficult for any single candidate to make a very sharp distinction with Allen."" Jackson, who has never held office, drew praise for his oratory, stressing the need for increased freedom and reduced spending. Marshall, one of the most conservative members of the House of Delegates, focused on his record passing a bill that paved the way for Virginia's lawsuit against the federal government on health care and another that allowed voters to decide that marriage should be between a man and a woman.