Four out of five U.S. adult voters are having buyer's remorse over the Republican Party's decision to nominate Donald Trump for president, according to a Huffington Post/YouGov poll released late Monday.

Of the 17 Republican candidates who set off for the nomination last year, 20 percent of all voters say the billionaire businessman was the party's best option for the nominee.

But one in three of Republicans agreed Trump was the party's best choice of the pool of candidates. That number was down from June when 44 percent said Trump was the best option.

When asked who they would support, Republicans did not abandon their two top performers after all. Trump received 29 percent of support while Texas Sen. Ted Cruz finished with 15 percent. Florida Sen. Marco Rubio knocked out the actual third-place finisher Ohio Gov. John Kasich with 14 percent of support. Kasich and the other 13 candidates finished with less than 10 percent each.

Hillary Clinton fared better than her Republican rival, but not by a lot. Approximately 30 percent of all voters said Clinton was the best option for the Democratic Party.

The poll was conducted online on Aug. 24-25 with 1,000 U.S. adults.