WASHINGTON -- Swing voters aren't angry. But they're tired of nasty, strident, partisan rhetoric, and they don't believe the economy is rigged against them.

Those are among the findings of a survey of swing voters in four states that are expected to be crucial to winning the November presidential election: Florida, Colorado, Nevada and Ohio.

The survey, conducted by Democratic pollster Peter Brodnitz for the Progressive Policy Institute, a center-left group that develops pro-growth ideas, illustrates how centrists crucial to a White House victory are not the voices being spotlighted throughout the primary season.

Unlike the primaries, which are often closed to independent voters and tend to attract more ideologically prone voters, those most in play this fall are not the people railing against the establishment or demanding radical change.

These swing voters make up about one-fifth of the electorate in the four states. Obama carried all four in 2012. His best showing among them was 52 percent in Nevada.

The last time Republicans won the White House, in 2004, President George W. Bush won all four, doing best in Florida, with 52 percent.

This year, swing voters don't identify closely with either party. They favored Obama four years ago, but they preferred congressional Republicans in 2014. Eighty-four percent call themselves independent, and 57 percent said they were moderates.

Eleven percent were liberal; nearly half of Democrats categorize themselves that way. About one-fourth said they were conservative, far less than the 69 percent of Republicans who put themselves in that camp.

Swing voters are clearly "less ideological ... and less angry" than intensely partisan voters, the survey found. "They are pragmatists who are focused mainly on economic growth and competitiveness."

The issue they want to hear most about is the economy, which most tend to see as fair or poor. But they're not enthusiastic about the pledge by Sen. Bernie Sanders, a Vermont independent running for the Democratic nomination, to expand the role of government. Nor do they necessarily agree with Republican Donald Trump about a crying need to "make America great again."

"Despite all the populist rhetoric displaying in both parties' nominating contests, the voters we interviewed don't seem particularly angry," the poll found.

Unlike Democrats, the swing voters are "more focused on growth than fairness, more concerned about spending, less optimistic about the economy" and more interested in finding ways to help corporate America.

Republicans can score if they can show that "Democrats are more focused on protecting the jobs of yesterday than creating the jobs of tomorrow" and putting brakes on corporate progress.

The swing voters do not see the economy as fundamentally broken or in need of dramatic repair. "They want to see companies, government and workers pulling together to help businesses compete and increase wages," the survey found.

That means improved training, education and retirement benefits, trade agreements with significant labor and environmental assurances, more infrastructure and a more efficient regulatory system.

These voters tend to be far more fiscally conservative and have less confidence in government than Democrats do.

A key question is whether these voters will go to the polls. Fifty-five percent voted in one of the last two elections, though turnout tends to increase in presidential election years.

But, the survey notes, "the polarizing tone of the Democratic and Republican nominating battles is unlikely to appeal to those voters."