WAUKESHA, Wis. — Wisconsin Gov. Scott Walker launched his bid for president in Waukesha, a Republican stronghold outside nearby Milwaukee. The governor chose the venue where he celebrated his past electoral successes to launch his latest campaign.

Walker is entering a field dominated by Jeb Bush's fundraising success and Donald Trump's media coverage. But Walker remains in the top tier in most national polls, still second in the RealClearPolitics polling average, and has held on to his lead in the first-in-the-nation Iowa caucuses.

As Walker tried to reach past the crowd of Wisconsinites who packed the auditorium, he previewed the pitch he will take nationwide later this week. He stressed the theme of "a fighter who wins," referencing his success winning three elections in four years while enacting conservative reforms in a mostly blue Midwestern state.

"You see, It doesn't matter if you're from a big city, a suburb or a small town, I will fight and win for you," Walker said. "Healthy or sick, born or unborn, I will fight and win for you. Young or old — or somewhere in between — I will fight and win for you."

This message is intended to contrast him with GOP rivals who have a strong track record of electoral success but have fewer battle scars from fighting over conservative issues or who have launched high-profile fights with liberals but haven't won them.

After much thought and prayer, Walker said, he decided to pursue higher office to ensure the country his children grew up in "is at least as great as the one we inherited."

Much of Walker's speech focused on reform, growth and national security, which he describes as "safety." He called for welfare reform, repealing Obamacare and a foreign policy that lets the world "know that there is no better friend and no worse enemy than the United States of America."

"We understand that true freedom and prosperity don't come from the mighty hand of the government, they come from empowering people to live their own lives and control their own destinies through the dignity that comes from work," he said. "Looking back, I realize my brother David and I didn't inherit fame and fortune from our family. What we got was the belief that if you work hard and play by the rules, you can do and be anything you want. That's the American Dream. And that is worth fighting for."

Walker emerged as the conservative favorite earlier this year after exceeding expectations with a speech in Iowa, but his poll numbers have since receded somewhat. He is the 15th declared Republican candidate and faces a number of other conservatives. Walker will try to recapture some of his momentum with a campaign swing this week.