RALEIGH – If Republicans enjoy an average wave election this year, they’ll take control of both houses of the North Carolina General Assembly.

In other words, they don’t need the political equivalent of a tsunami to batter down more than a century of Democratic power in Raleigh. They just need to perform about as well in 2010 as the winning political party has in recent wave elections in North Carolina.

For the purposes of analyzing legislative races in the state, I’ve looked at election returns going back to 1972. That year featured the reelection of President Richard Nixon and the elections of Jim Holshouser, North Carolina’s first Republican governor of the 20th century, and Jesse Helms, the first Republican elected to the U.S. Senate by popular vote. It was the year that true two-party competition arrived in our state.

Since 1972, there have been seven election cycles in which there was at least a five-percent gain in state house and senate seats by either the Democrats (in four of the seven years) or the Republicans (in three of them). Here are the wave elections by this definition:

• 1974 – The post-Watergate debacle for the GOP, when Democrats gained a total of 40 seats in the state legislature. Only one Republican was left standing in the 50-seat state senate.

• 1980 – The Reagan Revolution, when Republicans gained two seats in the U.S. House, five in the state senate, and nine in the state house.

• 1982 – A year of backlash against the Republicans, when the continuing recession and initial concerns about Reagan’s fiscal policies helped Democrats regain two seats in the U.S. House, four in the state senate, and six in the state house.

• 1984 – By this time, the economy was surging and Reagan soared in popularity. Republicans gained three seats in the U.S. House, six in the state senate, and a staggering 20 in the state house, thought that still left them with only 38 seats out of 120.

• 1994 – The Republican Revolution featured the largest-ever wave election, with a four-seat gain in the Congressional delegation, 13 in the state senate, and 26 in the state house. The latter now had a 68-52 GOP majority.

• 1996 – Another backlash year, this time driven by President Clinton’s reelection and his successful triangulation strategy against Newt Gingrich and the GOP. Democrats won two seats in the U.S. House, four in the state senate, and seven in the state house.

• 1998 – Democrats repeated their wave-election success in this impeachment-era midterm, electing John Edwards to the U.S. Senate (oops), gaining another U.S. House seat, and recovering five state senate and seven state house seats. The GOP no longer controlled the state house.

Obviously, each of these election cycles reflected the political controversies of their day and featured other idiosyncrasies. I’d also prefer to work with more cases than seven, but if you go back much further in time the analytical possibilities become severely constrained by North Carolina’s long history of one-party dominance.

Still, it’s worth observing that if you measure the gains across these seven wave elections, you will find average gains of two congressional seats, seven state senate seats, and 14 state house seats.

As it happens, many political prognosticators – looking at polling, campaign-finance reports, candidate quality, and other factors – seem to be predicting Republicans gains in North Carolina that look remarkably similar to the average for a post-1972 wave election.

For example, among congressional races the most competitive is the 8th District race between Democratic incumbent Larry Kissell and Republican challenger Harold Johnson. Most of the national analysts have this race pegged as either GOP-leaning or a toss-up. There’s another toss-up race in the 7th District between Democratic incumbent Mike McIntyre and Republican Ilario Pantano. At least two other seats may be in play, Bob Etheridge’s 2nd and Heath Shuler’s 11th, but they’re probably less likely to flip. A two-seat gain would be average for a wave election.

In the legislature, many analysts and political insiders I talk to think that Republicans will gain about seven or eight seats in the senate and a dozen to 14 seats in the house. Again, that would be about an average gain for a wave election.

I’m not saying these outcomes are at all certain. North Carolina Democrats are well funded and experienced at winning legislative races. I’m saying that, based on recent history, you don’t need to rely on outlandish scenarios or wishful thinking by the GOP to predict such outcomes. They’d be par for the course.

Hood is president of the John Locke Foundation.

p.s. If you want to read up on the key races that define the 2010 election cycle in North Carolina, there’s no better place to go than Carolina Journal’s Exclusive Series Covering the 2010 Elections.