By CBS3 Staff

PHILADELPHIA (CBS/AP) — New Jersey Gov. Phil Murphy and Delaware Gov. John Carney were among 12 Democratic governors to issue a joint statement on Wednesday defending American democracy, vowing that every valid ballot will be counted in the election after President Donald Trump sowed distrust during the first presidential debate.

Trump claimed without evidence Tuesday night that mail voting — surging in popularity during the coronavirus pandemic — is ripe for fraud, and he refused to say whether he would accept the results. He also called on his backers to scrutinize voting procedures at the polls, which critics said could cross into voter intimidation.

Without mentioning Trump by name, the governors noted his refusal last week to commit to a peaceful transition of power.

“Any efforts to throw out ballots or refuse a peaceful transfer of power are nothing less than an assault on democracy,” they wrote. “There is absolutely no excuse for promoting the intimidation or harassment of voters. These are all blatant attempts to deny our constituents the right to have their voices heard, as guaranteed in the U.S. Constitution, and to know the will of the people will be carried out.”

2020 Election Guide: Pennsylvania, New Jersey, Delaware

Signing the statement were Gretchen Whitmer of Michigan, Gavin Newsom of California, J.B. Pritzker of Illinois, Murphy, Ralph Northam of Virginia, Jay Inslee of Washington, Tony Evers of Wisconsin, Tim Walz of Minnesota, Kate Brown of Oregon, Steve Sisolak of Nevada, Michelle Lujan Grisham of New Mexico and John Carney.

The governors said all valid ballots cast in accordance with state and local laws must be counted and if Trump loses, “he must leave office — period.”

They wrote that elections are not “an exercise in controlling power” and that disenfranchising voters “strikes at the very heart” of democracy.

“We call on elected leaders at all levels, from both parties, to speak out loudly against such efforts in the weeks ahead,” they said.

A message seeking comment was left with the Trump campaign.

(© Copyright 2020 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)