Virginia Gov. Robert F. McDonnell is working hard to help Republicans win control of the state Senate in the Nov. 8 elections, which would give the GOP total sway in Richmond for the first time in a decade. Such a sweep might enhance his growing national reputation — and his vice presidential prospects in 2012.

But it also could prove a mixed blessing, forcing McDonnell to answer a question: What kind of Republican is he?

So far, Virginians love McDonnell, and the sentiment is spreading beyond state lines. A policy wonk with a pragmatic record, conservative street cred, civil manners and good looks, McDonnell has overcome early stumbles — such as failing to mention slavery in a proclamation for Confederate History Month — and enjoys enviable approval ratings. In the buzz about GOP vice presidential possibilities, McDonnell is all the rage.

He was known in his years as a state lawmaker as a social conservative. Few who served with McDonnell in the House of Delegates were surprised at the contents of his 20-year-old law school thesis, which surfaced during the 2009 gubernatorial campaign: It attacked liberals, social programs, homosexuality, birth control, out-of-wedlock sex and the decline of the traditional family.

But since becoming governor, McDonnell has let fire-breathing House Republicans lead the charge against abortion, contraception, illegal immigrants and laws restricting guns. When much of that legislation died in the Democrat-controlled Senate, McDonnell was mum. And while he did sign into law in March a rewrite of state regulations that could force many of Virginia’s 21 abortion clinics to close, he did so with a minimum of fanfare.

Meanwhile, he has plugged away at the mechanics of state government — balancing the budget, borrowing money to build roads, closing some state commissions. That’s just what Virginians have come to expect from their governors in what is regularly listed among the best-managed and business-friendliest states. Hence McDonnell’s nearly 3-to-1 approval ratings.

But what if the state Senate is captured next month by a field of Republican candidates far more conservative than the retiring generation?

A stack of right-wing legislation would land on the governor’s desk: bills conferring rights on fetuses, repealing the state law limiting handgun purchases to one a month, forcing state colleges and universities to allow handguns on campus, requiring welfare recipients to undergo screening for illegal drugs, compelling schools to collect information on students’ immigration status, and allowing employers to fire workers for not speaking English. The budget, too, might be subject to radical revision, with funds raided from education, public safety and health programs.

That’s not the agenda most Republicans are talking about in this fall’s campaign. Most stick to national GOP orthodoxy — Lower taxes! Shrink government! Scrap regulations! — with scant mention of hot-button issues, or even Virginia itself.

But it’s an agenda most of them support — and it could redefine not only Virginia politics but also McDonnell’s governorship and his image as a moderate conservative.

That might be perfect positioning for a possible vice president — if, say, Mitt Romney decides he needs a running mate with right-wing appeal. It’s unlikely to sit as well with millions of middle-of-the-road Virginians.

The writer is a member of the editorial page staff. His e-mail address is