"In the United States of America, democracy is the foundation of our way of life," the Democratic presidential hopeful said. "And what happened in Arizona is a disgrace. I hope that every state in this country learns from that and learns how to put together a proper election where people can come in and vote in a timely manner and go back to work."
Sanders said during a news conference a supporter emailed his campaign complaining about the long waits.
"Whatever the cost of that problem is people in the United States of America shouldn't have to wait five hours in order to vote," he said. "We do not know how many thousands of people who wanted to vote in Arizona did not vote."
Liberal activists are also demanding an investigation into what they see as possible voter suppression as a result of Maricopa County officials' decision to reduce the number of polling stations as a cost-saving measure.
The activists are planning to outline their frustrations at a press conference that the reduction in polling places led to long lines and dissuaded voters from casting ballots during Tuesday's presidential primary.
On Wednesday, Arizona Gov. Doug Ducey tweeted
a statement saying the delays were "unacceptable" and that the state's "election officials must evaluate what went wrong" to make sure it doesn't happen again.
"If people want to take the time to vote they should be able to, and their vote should be counted," Ducey wrote.
Ducey suggested simplifying the primary process by allowing independents to vote in presidential primaries.
Maricopa County Recorder Helen Purcell said Wednesday that she took "full responsibility for what happened yesterday" at polling stations, at a Maricopa County Board of Supervisors meeting.
Purcell, a Republican, initially defended the closings on Tuesday night, telling Fox 10 Phoenix voters could have voted via early ballots rather than risking waiting in line.
There were at least 200 polling stations in 2012 and 400 in 2008, but just 60 open Tuesday, in Maricopa County, the most populated county in Arizona.
"If U are standing in very long line to cast your ballot today, this is what @AZGOP's claimed imaginary voter suppression looks like #AZVotes," tweeted Arizona State Sen. Martin Quezada, a Democrat and Sanders supporter.
The Arizona Democratic Party has asked
voters who had trouble voting to complete an online form describing their challenges. The group plans to share the information with the Arizona Secretary of State Michele Reagan, a Republican.
Activists allege that decreasing the number of polling locations from 200 to 60 left some residents completely lacking any or only one polling location in their neighborhood.
"Voting is a right not a privilege -- it should be fair and accessible to all our people," said a post
on the Arizona Black Voter Alliance Facebook page.
Republican officials previously defended the closings, saying there was less demand for polling places because so many voters mailed in their ballots.
"They're not to blame for standing in line. But they went to the polling places. They could have voted early or that was their option in this instance," Purcell said. "I don't mean to blame voters. I think it's wonderful voters went to the polls."
She added that officials chose polling places to close based on areas with high mail-in ballot returns.
The delays appeared to frustrate both Republican and Democratic voters alike.
The editorial board of the Arizona Republic, the state's largest paper, said some residents "waited in line more than five hours to vote in an election with high stakes for their country."
The board noted
that Pima County, Arizona had 130 sites, more than twice as many as Maricopa County, for one-quarter as many voters.
"That led to ease of voting in the southern part of our state, and disaster in urban Phoenix," they wrote.
Purcell said she's willing to reevaluate the decision.
"We will certainly look at this and see if we need to do something different," she said Tuesday.