Des Moines, Iowa (CNN) Former New York Mayor Michael Bloomberg says now that Democrats have won the House, they have to "do something."

"If they just sit back and do the same thing that the people they just ousted did then I'm not gonna be happy and I've told Nancy Pelosi that," said Bloomberg, who spent more than $110 million in last month's midterms to help Democrats wrest control of the House from Republicans.

Bloomberg, who is considering a presidential run in 2020, spoke to CNN on Tuesday during a daylong trip to Iowa -- a crucial early voting state -- where he was promoting his new documentary about climate change.

The media and financial data mogul made multiple stops across the state, including at an electric company in Cedar Rapids and a community college in Ankeny that trains student to work on wind turbines. In a classroom with turbine simulators, Bloomberg told students they were building promising careers in well-paying green jobs.

Bloomberg said he wasn't visiting Iowa to solicit votes -- yet.

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