"If he is the nominee, I will be voting for him, I will be supporting him," Jindal, who also ran for president this cycle, said on CNN. 
The former Louisiana governor argued that under Trump, Republicans have a shot at repealing ObamaCare and putting a conservative justice on the Supreme Court, compared to their prospects with Clinton in the White House.
"I'm not happy about it. I don't think he's the best-qualified candidate. I don't think he's the one most likely to be successful, but I would vote for him over Hillary Clinton," Jindal said.
Jindal was one of the most outspoken critics of Trump before ending his campaign in November, calling Trump "insecure," "weak" and "dangerous" during a speech two months earlier. 
Jindal, who in February endorsed Florida Sen. Marco RubioMarco Antonio RubioColbert: Students taking action on gun violence 'give me hope' Lawmakers feel pressure on guns Florida lawmaker's aide fired after claiming shooting survivors were 'actors' MORE, predicted on CNN that Trump would not "do a lot of the things that he's said he's going to do."
"I don't think he's a conservative at heart," Jindal remarked. "I don't think he's opposed to big government; I think he just wants to be the one running big government."