In 1998, Shaun Kenney and Del. Robert D. "Bobby" Orrock Sr. seemed from the outside to be on the same page. Both were Republicans in Spotsylvania, like much of Virginia newly in the GOP column, and the 19-year-old Kenney agreed to work for Orrock as a legislative intern.

But Kenney now says that even then he wasn't totally comfortable with what he viewed as Orrock's willingness to budge on issues such as taxes and abortion.

Seven years later, the split between Kenney -- who calls himself a "pure" conservative -- and Orrock has manifested itself in a political race for the Republican nomination for the House of Delegates in the 54th District.

The main reason Orrock finds himself with a primary challenger for the first time since he took office in 1990 is what happened on April 27 of last year. That's when Orrock cast his vote with a group of 17 Republicans for a tax increase Gov. Mark R. Warner (D) said would preserve the state's bond rating and provide needed services for a booming population. But anti-tax forces vowed they would be back the next year, and they are, funding challengers to at least six of the 17.

Kenney, now 27, said he had been lobbied since last summer by state and local Republican activists to run against Orrock. But while the Spotsylvania County Republican Party chairman was furious about the tax hike and wanted to run, he had three young children and hopes for law school.

But there he was last month in front of the Spotsylvania County courthouse, announcing he was seeking the GOP nomination for the 54th, which covers much of Spotsylvania County and some of Caroline. There are 90,000 people in the district, up from 70,000 in 2002.

Orrock, 50, said the attack on his vote last year is Monday-morning quarterbacking.

"You have to deal with the budget as you see it then," he said, noting that local governments across the state were waiting to set their budgets and many were proposing tax hikes themselves. "The state has to pay its bills."

Kenney has been working on campaigns since he was in high school, has been chairman of the Republican Party in Fredericksburg and Spotsylvania and keeps an online journal -- or "blog" -- mostly devoted to promoting positions such as a cap of 5 percent a year on property tax increases, school vouchers and his pleasure that Cardinal Joseph Ratzinger was selected pope.

Kenney, who works as a program analyst for a defense contractor, JRM Technologies in Fredericksburg, said he believes last year's tax increases were unnecessary. The government could save money by privatizing expenditures such as road contracts and offering vouchers for private schools that cost less than a public school education, he said. And, he noted, the state now expects to wind up collecting at least $1 billion more in tax receipts than it had originally anticipated -- significantly easing the financial strain.

Whether voters are in a mood to punish or praise Orrock and the other GOP defectors isn't yet known, particularly in districts such as the 54th, where the population is growing and changing by the day.

Kenney said that if elected, he would introduce legislation to designate that "life is at conception." He criticized Orrock for voting against a bill that would have required that parents be notified if a minor received treatment for sexually transmitted diseases or pregnancy, among other things. Orrock said it was irresponsible to do anything that might keep young people from seeking accurate medical information.

"I'm unabashedly pro-life but I'm not going to vote for a bill just because it sounds good when the net effect may be something opposite," said Orrock, who teaches agricultural business at Spotsylvania High School.

Both candidates have received a significant chunk of their contributions from political action committees formed to either unseat or support the Republicans who voted last year for the tax hike.