Ivanka and Eric Trump failed to change their party affiliation to Republican in time for the closed New York primary, leaving them unable to vote for their father

Two of Donald Trump’s children won’t be able to vote for their father in the New York primary next week, after failing to change their party affiliation in time for the state’s 19 April primary.

“They feel very, very, guilty,” Donald Trump said of his two children, Ivanka and Eric, who are both New York residents.

Both Trump children are registered to vote as independents, and therefore cannot participate in New York’s Republican primary.

The deadline for the two to change their party affiliation under the state’s stringent voter registration laws was 9 October 2015. In contrast, the deadline for new voters to register was on 25 March, nearly a month before the Empire State’s contest. Ironically, considering her miscue, Ivanka Trump has appeared in videos encouraging Trump supporters to register to vote and change their party affiliation since missing the deadline.

Two of Trump’s children, though, will still be able to vote for the Republican frontrunner. His son Donald Jr is a registered Republican in New York and his daughter Tiffany is registered as a Republican in Pennsylvania where she is a student at the University of Pennsylvania.

Trump is sailing as the frontrunner in New York, but he needs every vote he can muster if he is to cross the 50% mark statewide and in each congressional district. Any candidate who crosses that threshold in a given district gets all the delegates at stake. If no candidate crosses the threshold, the delegates are awarded proportionally.

The Republican candidate is not the only candidate likely to be hurt by New York’s unique combination of a closed primary and arcane election rules. Vermont senator Bernie Sanders has polled significantly better with independents than Democrats. In addition, New York has a strong left-leaning third party, the Working Families Party, whose members will not be allowed to participate.

Here’s Trump’s phone interview with Fox on the topic, reposted from the intro: