US ELECTIONS: Ernst holds onto Iowa Senate seat after race tests biofuel support

US Senator Joni Ernst, Republican-Iowa, held onto her seat after a tight race that tested her support of biofuel makers and knowledge of commodity prices.

Ernst drew 51.6% of votes to Democratic challenger Theresa Greenfield's 45.4%, according to preliminary results from The Associated Press, which called the race.

In her first term, Ernst played a key role in White House negotiations over the US biofuel mandate, defending the Renewable Fuel Standard on behalf of biofuel makers as oil refiners pushed for exceptions and lower blending requirements.

Ernst stumbled during an Oct. 15 debate when asked to give the breakeven soybean price after Greenfield adeptly answered a similar question on breakeven corn prices. The video clip briefly went viral as an example of the basics a farm-state senator should know.

Greenfield sought to blame Ernst for the Trump administration's widespread granting of waivers to small oil refineries, arguing she should not have voted to confirm Environmental Protection Agency Administrator Andrew Wheeler while knowing that he would likely continue to grant the exemptions.

"As long as I'm there in the United States Senate, I will be fighting to ensure the future for biofuels," Ernst said in a Sept. 28 debate. "I have gone toe-to-toe with even members of my own party to make sure we're upholding those Renewable Fuel Standards."

Ernst also promised to vote against any climate legislation like California's recent goal to end new sales of gasoline-powered passenger vehicles by 2035. She said it amounted to "outlawing fossil fuels, ethanol and biodiesel in a matter of 15 years."

"That is not something we should be supporting right here in the state of Iowa," she said.