But despite calls for him to drop out of the race — and threats of withholding crucial advertising dollars in the fall — Akin said Tuesday that he was remaining in the race. He had until 5 p.m. to remove his name from the Missouri ballot without a legal challenge required, but that deadline elapsed.

During an appearance Wednesday on ABC's "Good Morning America," Akin joined Walsh in chiding "party bosses."

"I don't know the future, but I do know this. I knew that the party voters took a look at our hearts, understood who we were, had a chance to meet us in many, many different ways and made a decision," Akin said. "And it makes me uncomfortable to think that the party bosses are going to dictate who runs as opposed to the election process."

Akin also said that GOP vice presidential candidate Paul RyanPaul Davis RyanRepublicans are avoiding gun talks as election looms The Hill's 12:30 Report Flake to try to force vote on DACA stopgap plan MORE contacted him Tuesday and urged him to exit the race.

"He advised me that it would be good for me to step down," Akin told NBC News. "I told him that I was going to be looking at this very seriously, trying to weigh all the different points on this."