Donald Trump not backing down from dismissive John McCain comment

Once again, Donald Trump isn't backing down from comments that have inflamed the Republican presidential race.

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At an Iowa Republican forum Saturday, Trump dismissed Arizona Sen. John McCain's reputation as a war hero, saying McCain was merely captured in Vietnam and "I like people who weren't captured."

That's caused an uproar. But Trump isn't repentant.

On ABC's This Week, broadcast Sunday, the reality TV personality insisted: "I will say what I want to say."

Trump went further Sunday when he took to Twitter to demand McCain apologize for remarking that Trump was "firing up the crazies" with his controversial rhetoric about illegal immigration. He also reiterated his stance that McCain is not doing enough to help war veterans.

And in a statement, Trump says he has a strong record of supporting veterans and that politicians such as McCain have failed veterans.

Trump shook up the race weeks ago when he branded immigrants from Mexico as rapists and drug dealers.

Several Republican rivals for the party's presidential nomination have upbraided him for his remarks on McCain.

Jeb Bush says of Trump: "Enough with the slanderous attacks."