Forget about bipartisan compromise in Virginia. In a series of actions this spring, anti-tax activists have killed the prospects even for one-party agreement in Richmond.

Over the winter, Republican Gov. Robert F. McDonnell and top lawmakers crafted a major transportation bill — the first such bill to be successful in the commonwealth in more than 20 years — to deal with the choking gridlock of our region. With the assistance of Lt. Gov. Bill Bolling (R) and House of Delegates Speaker Bill Howell (R-Stafford), the governor secured enough votes in the Republican-controlled chambers to pass the $1.4 billion-a-year plan, including $1.2 billion in new tax revenue.

Now, for the second time in two months, the anti-tax activists who tried but failed to block the measure have had their revenge. On June 11, voters blocked the renomination of two high-ranking and long-serving Republican delegates who voted for the bill: Transportation Committee Chairman Joe T. May (Loudoun) and Beverly Sherwood (Frederick), who chairs the Agriculture, Chesapeake and Natural Resources Committee. Howell was also targeted, but he was renominated easily.

This slap-down of Republicans willing to compromise came on the heels of a party convention in May where activists backed very conservative choices for a statewide ticket, led by gubernatorial candidate Ken Cuccinelli, now the state’s attorney general. Those same activists had previously dispatched Bolling’s planned nomination challenge by forcing the convention, where conservatives were sure to dominate, rather than a primary.

He may not have been on the ballot, but anti-tax activist Grover Norquist was the real winner in these GOP battles.

Because of careful line-drawing by the Republican majority in the House, most Republican incumbents are much more worried about challenges from other Republicans than from any Democrat in a general election. Taken together, the experiences of Bolling, May and Sherwood are sure to give pause to any GOP lawmaker willing to listen to even a budgetary compromise brokered by a future Republican governor.

The centrist voters who control general elections can do little more than ratify the primary results in highly gerrymandered districts. The GOP has a two-to-one majority in the House, even though Democrats are highly competitive in statewide elections (the state’s two U.S. senators are Democrats, and Democrats have won two of the past three gubernatorial contests). The seats held by May and Sherwood are both heavily Republican.

In the past, Republicans sought to appeal to the state’s centrist majority by providing political space in the party for less conservative voices such as former senator John Warner and former representative Tom Davis, as well as several state senators who were willing to work with Democrats at least some of the time. While conservatives may sometimes have fumed, Warner, Davis and that team of moderate Republican state senators proved very effective campaigners — and legislators.

But indulgences are no longer granted. Now, when Republicans with even solid conservative records try to say something other than “no,” they face the wrath of a well-organized activist cadre that can control a nomination struggle in which fewer than 5,000 votes are cast. (The average House district in the state has about 80,000 residents). To call the governor and the other Republicans who brokered the transportation compromise “moderate” is only possible if one pushes the definition of moderate in a far more conservative direction than was the case in Virginia even a few years ago.

What will the future of politics in Richmond look like? Just look to another legislative assembly 100 miles to the north, where extremist fervor, gerrymandered districts and scorched-earth politics have had more time to take root.

The writer is a professor of political science and international affairs and director of the Center for Leadership and Media Studies at the University of Mary Washington in Fredericksburg.