Four of the five candidates running for the Democratic presidential nomination attended the Iowa Federation of Labor Convention in Altoona on Thursday. The forum began with a three-minute speech by each candidate, and then a series of questions were asked by panelists about labor issues such as minimum wage, infrastructure jobs, immigration, and trade.

Many of the candidates shared the same views on minimum wage and the necessity to raise it.

“It’s been a long time since the minimum wage was last raised,” said Jim Webb. “The last time it was raised I was a member of the Senate. I do believe that we need to raise it, and even the discussion as you’ve seen as increased the compensation in many places of the country.”

Martin O’Malley touched on the necessity to focus more jobs on clean energy and combating climate change.

“I am the first candidate in this race to advocate and put forward a plan to take us to a clean, 100 percent paid electric grid by 2050,” said O’Malley. “We can create millions of jobs in the course of building out the new infrastructure required to face this threat of our time.”

Second-place contender Bernie Sanders appeared via video as the U.S. Senate is still in session. He talked about his opposition to the Trans-Pacific Partnership spearheaded by the Obama administration.

“You know, I am a friend of President Obama,” said Sanders. “I have worked with him on many issues, but he is dead, dead, dead wrong on this whole TPP thing.”

Sanders went on to explain that he would go back to the drawing table and bring in more groups to discuss a better trade deal with countries involved, as well as leave corporate interests out of the negotiating process.

“When big money speaks, when corporate America speaks, when Wall Street speaks, when the drug companies speak, it appears that no matter what political party the president belongs to,” said Sanders, “they end up going along with these trade agreements.”

Front-runner Hillary Clinton was not at the event. Her campaign said Clinton had a prior engagement.