By Andrew Clark, Shea Smith, and Page Jones, Huffington Post Politics.

Renewable fuels and the controversial standards surrounding them are repeat hot topics of debate during the Iowa caucuses, and the current crop of presidential candidates are not cowering away from the issue.

Republican presidential candidate Donald Trump said Tuesday at the 10th annual Iowa Renewable Fuels conference that he supports the notion to maintain the standard, a declaration that must have boded well with many citizens of a state with 41 corn ethanol plants in attendance.

"As president, I will encourage congress to be cautious in attempting to charge and change any part of the (Renewable Fuel Standard)," Trump said at the summit, closely accompanied by his script. "Energy independence is a requirement for America to become great again."