In the wake of the 2012 elections, Republicans are being warned once again that they need to compromise their principles to win at the ballot box. That the only way to win the center is to move to the center.
If this were true, Barack Obama would not be president today—and I would not be governor of Wisconsin.
When I was first elected as Milwaukee County Executive in 2002, pundits said it was a fluke—a Republican elected in a heavily Democratic district in a special election in the wake of a political scandal. To stay in the job, they said, I would have to move to the middle. Instead, I governed as a conservative reformer and won three consecutive elections as county executive, each one by bigger margins. The last one, in 2008, was especially noteworthy. Mr. Obama won Milwaukee County with 67.5% of the vote; I won with nearly 60%.
As governor of the state, my administration reformed collective bargaining in the public sector against enormous odds, turned a $3.6 billion deficit into a $760 million surplus, and cut taxes. In response to the union reform, opponents mounted a recall election in 2012. It was contentious—yet after enduring a hundred thousand or more protesters and tens of millions of dollars in negative ads, we won the recall by a bigger margin than in the gubernatorial election in 2010.
And here is where the results get intriguing: Exit polls showed that roughly one in six voters who cast their ballots for me in the June 2012 recall also planned to vote for Mr. Obama a few months later. These Obama-Walker voters constituted about 9% of the electorate.
 
President Barack Obama Corbis
 
Polls show that about 11% of the people in Wisconsin today support both me and the president. There are probably no two people in public life who are more philosophically opposite—yet more than one in 10 approve of us both.
To make a conservative comeback, Republicans need to win these Obama-Walker voters and their equivalents across the country. In the Wisconsin recall election, we mobilized conservative voters by standing up for conservative principles against enormous pressure. But we also persuaded at least some of President Obama's supporters to support us, too.
There are independent, reform-minded voters in every state. In times of crisis, they want leadership—from either party. What I have learned is that if you step forward and offer a reform agenda that is hopeful and optimistic, they may give you a shot. More important, if you deliver, they will stick with you.
The way Republicans can win those in the middle is not by abandoning their principles. To the contrary, the courage to stand on principle is what these voters respect. The way to win the center is to lead.
That's why those arguing that conservatives have to "moderate" their views if they want to appeal to the country are so wrong. If our principles were the problem, then why are so many Republican governors winning elections by campaigning on them? Since Barack Obama took office in 2009, the GOP has gone from controlling both the legislature and governor's mansion in nine states to 23 states today. Not one sitting Republican governor has lost a general election since 2007.
Republicans did not win those races by running from principles. They won by applying principles in ways that are relevant to the lives of citizens.
In Washington the fight is over "fiscal cliffs," "debt limits," "sequesters" and "shutdowns." In the states, Republicans focus on improving education, caring for the poor, reforming government, lowering taxes, fixing entitlements, reducing dependency, improving health care, and creating jobs and opportunity for the unemployed.
Republicans need to do more than simply say no to Mr. Obama and his party's big-government agenda. They can offer Americans positive solutions for the nation's challenges—to reduce dependency, and create hope, opportunity, and upward mobility for all citizens. They need to make not just the economic case for conservative reforms but the moral case as well—showing how conservative policies and ideas will make America not only a more prosperous society but a more just and fair one as well.
When I faced the need to reform collective bargaining in the government, I wanted to win, but I wasn't afraid to lose and didn't worry about getting re-elected. That was profoundly liberating.
Too many people in politics today spend their time trying not to lose instead of trying to do the right thing. They would better serve the country by worrying more about the next generation than the next election. The irony is that politicians who spend more time worrying about the next generation than about the next election often tend to win the next election—because voters are starved for leadership.
Americans reward leaders who offer positive solutions, keep their promises and get results. If Republicans do that, Americans will stand with them. I know because they stood with me.
Mr. Walker, a Republican, is the governor of Wisconsin and the author of "Unintimidated: A Governor's Story and a Nation's Challenge" (Sentinel, 2013