The GOP's Senate health care bill collapsed on Monday evening after two more senators announced they would not back the bill.
Second on the list was unemployment, with 13 percent of respondents saying it was the most important issue.
The delayed vote on the bill has yet to persuade senators of its merits.
With Senate Republicans planning to rewrite their bill, it’s hard to predict the details of the final proposal.
Medical travel is becoming more popular as millions of Americans fear losing their health care coverage or face long waiting times.
Top aides to Charles Koch, the billionaire energy magnate, said the Senate bill does not go far enough to dismantle former President Barack Obama's signature healthcare law, also known as Obamacare.
The president said Obama had used the same words he used to describe the healthcare bill.
President Donald Trump can only afford to lose two GOP votes.