DES MOINES, Iowa (AP) — Democrats' plans for virtual presidential caucuses in Iowa and Nevada are effectively dead as the national party chairman said Friday the results would be vulnerable to hacking and abuse.

Tom Perez, chairman of the Democratic National Committee, declared his opposition to plans for telephone voting submitted by the key early voting states of Iowa and Nevada, envisioned as part of the national party's efforts to increase participation in the 2020 nominating fight.

"We concur with the advice of the DNC's security experts that there is no tele-caucus system available that...