The candidates debated at National Park Community College in Hot Springs.
A recent Talk Business/Hendrix College poll shows Republican Tom Cotton favored to win the race.
The main issues discussed at Tuesday night's debate were the economy and health care.
The candidates laid out their visions for what they'd do in Washington:
"I want to talk about making government smaller, making it more effective as opposed to making it intervene evermore in the marketplace, which causes distortions, which takes more power and money away from Arkansans and puts it in the hands of bureaucrats in Washington," said Tom Cotton.
Gene Jeffress said, "This determines where we're going to go in the next few years. Are we going to do away with Medicare, Social Security, these things are important."