CNN's Dana Bash will moderate the town hall from Drake University in Des Moines, Iowa.

After facing criticism for having been found to accept the second highest number of campaign contributions from the oil and gas industry, O'Rourke signed a pledge earlier this month to reject oil and gas executives' donations on top of continuing his Senate race policy of not accepting donations from outside groups and super PACs . He also unveiled a plan to combat climate change that same week that would invest $5 trillion in infrastructure and innovation projects over 10 years with the goal of net-zero emissions by 2050.