The Associated Press

WASHINGTON - Rep. Stephanie Herseth Sandlin is hitting the campaign trail for Democratic presidential candidate John Edwards, traveling to Iowa to try to persuade the state's farmers to vote for him.

Herseth Sandlin, D-S.D., officially endorsed Edwards in April, saying he is the best candidate for rural voters. She was scheduled Friday to speak to the Iowa Farmers Union State Convention in Des Moines, Iowa.

"He's the one that has the most truly comprehensive plan and he doesn't just talk about rural America," Herseth Sandlin said before the speech.

Edwards, who was born in Seneca, S.C., has a proposal that calls for increased investment in rural small businesses, education, health care and resources to fight methamphetamine abuse.

He has said the nation's need to wean itself off foreign oil could create jobs and help rural economies with the development of alternative power such as biofuels and wind turbines.

Herseth Sandlin said she also likes Edwards' positions on health care and ways to ease poverty.

Edwards is fighting several Democrats for the nomination, including frontrunning Sens. Hillary Clinton of New York and Barack Obama of Illinois.

Obama recently convened a rural summit in Iowa, saying Washington has ignored rural America for too long. Clinton has also attempted to appeal to rural voters.

Herseth Sandlin said Edwards has organized strength in rural communities.

"It's still very early, and there's always an opportunity for someone like John Edwards," she said.

Edwards, who served one term in the Senate, was the running mate of Sen. John Kerry, D-Mass., who lost the 2004 race to President Bush.

South Dakota Sen. John Thune, a Republican, has endorsed Sen. John McCain, R-Ariz., for the GOP nomination. Sen. Tim Johnson, a Democrat, has not officially endorsed a candidate for president.