Here’s the scenario. A special congressional election in southwest Pennsylvania becomes the center of national attention as control of the House hangs in the balance come fall. The Democratic candidate runs as an anti-Nancy Pelosi, pro-gun, pro-life candidate concerned with economic issues — in other words, as a centrist.

Meanwhile, the Republican nominee, for the most part, runs a mostly negative ad campaign trying to tie his opponent to Pelosi and her liberal agenda. Both national parties make huge multimillion-dollar investments in the outcome for a district that is going to disappear in a matter of months thanks to redistricting. Meanwhile, the media has upped the ante by declaring this a bellwether race whose outcome will signal whether the minority party is about to win a wave election or the majority will defy the odds and hold on to the House.

As one political consultant told CBS News, “If the Republican doesn’t [win], I think us pundits in Washington are going to have to revise our thinking about whether this is a wave election year for Republicans.”

Wait a minute. A wave election year for Republicans?

No, that wasn’t a misprint. It was from 2010, and the race was a special election for a southwest Pennsylvania seat — what was then the 12th District — which incorporated some of today’s 18th District. The seat had been held by the late Democratic Rep. John Murtha for more than three decades, but his unexpected death had created a hotly contested special election.

Democrat Mark Critz, Murtha’s longtime district director, threw his hat in the ring and, like Murtha, opted to run as a more conservative Democrat, understanding the centrist political nature of the district. Along with being anti-abortion and pro-gun, Critz opposed Obama’s health care plan and favored tax cuts for small businesses.

Rather than run as a positive alternative to Critz, however, Republican Tim Burns’ campaign strategy relied almost entirely on a string of negative ads painting his opponent as nothing more than a liberal Pelosi clone.

Critz won, 53 percent to 45 percent. That kind of campaign cost Burns and Republicans a seat they could have won.

Watch: Ryan — Democrats’ Success in Pennsylvania 18 Not Repeatable

Negative messaging

The race was a perfect example of the type of campaign model I’ve watched consultants sell and resell to Republican candidates (and Democratic consultants to theirs) for decades. It’s a model dependent on attacks that are often personal; ideological arguments and the kind of campaign rhetoric that appeals to the base but can be a barrier to reaching the important Big Middle that decides elections these days.

For years, some campaign consultants have given more weight to negative messaging than to what voters in any given district care about and how to connect with them through a candidate’s policies and vision.

Now, fast-forward to 2018, to the same neck of the woods in southwest Pennsylvania. Change the candidate from Critz to Conor Lamb and you’ll see some of the same elements. Consultants and pundits have put some of the blame on the GOP candidate, but they saved some of their fire for the recent tax cut legislation, claiming it failed to energize voters.

Maybe, but the external polling I’ve seen showed the Republican nominee, Rick Saccone, ahead in the race when at least some pro-tax cut messaging was on the air up to mid-February. Granted, his lead at that point, however, was still small and reflected an underperformance. But once the campaign returned to a strategy of trying to join Lamb and Pelosi at the hip, Saccone’s numbers began to slip and momentum seemed to shift to the Democrat.

For Lamb, countering the attack was easy. He had already said on many occasions that he would not vote for Pelosi for leader. End of story. End of the attack’s effectiveness. But not the end of the ad buy.

If the Republican underperformance in special elections over the past year is any indication, the same campaign strategy that has dominated much of the party’s consulting community for the past fifteen years may finally have fallen victim to the law of diminishing returns. Which brings me to the point of this stroll through Pennsylvania electoral history.

A political gift

In 2010, the special election in Pennsylvania’s 12th District was a tough loss when history dictated Republicans should’ve expected to pick up seats in congressional elections in a nonpresidential year. In reality, that defeat ended up being a gift to the GOP.

The unexpected loss jolted Republicans out of their complacency. It was a “just-in-time” wake-up call that solidified the direction then-House Minority Leader John Boehner and his leadership team decided on to define Republicans as the alternative party and not just an opposition party. They would go beyond “checks and balances” to offer an agenda focused on jobs and what a GOP majority would do.

This year’s midterms don’t have to be a referendum on President Donald Trump any more than 2010 was about putting limits on Barack Obama’s presidential power. They need to be about what congressional Republicans have accomplished, with an emphasis on tax reform, jobs and wages. That means talking specifics over and over again, explaining to voters how the tax law will impact them directly and long term, and what the legislation will do for the future of the country.

Republicans have a powerful story to tell but they’ve got to sell it — and sell it hard.

With a positive strategic message, based first and foremost on tax reform, Republicans have the opportunity to turn conventional wisdom’s dour view of their electoral prospects upside down — an opportunity, not an inevitability. Ultimately, the question the electorate is going to ask is, “Have I seen progress toward the change I voted for in 2016?” That means voters are going to look at whether Republicans in Congress earned their trust by moving toward that change.

So while Pelosi’s statements leave many voters very willing to listen to what the GOP has to say, Republicans need to close the deal, given that they’ve had the responsibility of governing.

The blue wave may yet come. But sometimes a little perspective is a good idea. Critz’s congressional career lasted 20 months, and Republicans did regain the House in 2010 in part by understanding what happened in the Critz-Burns race.

The Lamb-Saccone special election was an important “preseason” game that showed the strength and weaknesses of current Republican (and Democratic) political strategies and campaign abilities. There is still time for Republicans to remember the lessons of Pennsylvania’s 12th in 2010, learn from Pennsylvania’s 18th this month, and craft a positive strategy for the fall that can deliver results in a challenging environment.