Republican presidential frontrunner Donald Trump revealed on Monday that two of his own children, Ivanka and Eric, failed to register in time to vote in New York's April 19 primary.

On Fox News' Fox and Friends, the billionaire said, “They feel very, very guilty.” When asked if he would cut off their allowances, he replied, "No more allowance." The deadline for registered voters to change party enrollment was Oct. 9, 2015.

.@realdonaldtrump says Eric, Ivanka feel "guilty" for not registering as Republicans in time to vote pic.twitter.com/NmWBn38Hn5

— POLITICO (@politico) April 11, 2016

While the Trump children's lack of voter support was accidental, Democratic presidential candidate Hillary Clinton was more intentionally anti-Trump in a new attack ad. 

Clinton's ad calls Trump out by name and slams his proposed ban on Muslim immigration:

While Clinton's ad is merely pointing out some of Trump's highly publicized beliefs, her attack might work. In a recent poll conducted by the Associated Press, Americans trust Clinton over Trump on issues like immigration, healthcare, and the economy.