A lawsuit filed by the Democratic Party challenging Arizona’s election practices is the latest front in the legal battle over voting rights since the Supreme Court gutted the Voting Rights Act.

The legal complaint gives a glimpse into the meticulous details involved in election planning, details that, when overlooked, could have major implications for voters on Election Day. It zeroes in on Maricopa County, Arizona’s most populous county, where March’s presidential preference election featured hours-long lines that made it extremely difficult, if not impossible, for many to vote.

Democrats say that many of the problems would have been prevented had the Supreme Court not taken a major swipe at the Voting Rights Act in 2013’s Shelby County v. Holder decision. Due to that decision, Arizona was no longer required to submit any changes to its voting regulations for federal approval. Now Democrats are asking a federal judge in Phoenix to examine Maricopa’s plans for carrying out its general election in November and make sure minority voters will not be disproportionately burdened by the system. It is also asking the judge to block state laws that Democrats say will also disenfranchise minorities and other Democratic-leaning voters.

Here are 5 points on how Dems say Arizona screwed up its election.

Maricopa County low balled how many voters would show up.

For the 2016 presidential primary, Maricopa instituted a voting center system, a reform that can make voting easier if implemented correctly, because voters can vote at any location, rather than just in the single polling precinct they’re assigned to. The lawsuit alleges Maricopa made flawed assumptions in their roll out of the vote centers, including only setting up 60 vote centers to replace 200-plus precincts from the 2012 elections.

To come up with that number, as Maricopa officials previously explained to TPM, they planned for only the eligible, party-registered voters who had not requested mail-in ballots, and assumed that out of that pool of voters, around the same percentage would show up (about 20-25 percent) as in the last presidential primary where both parties were contested.

However, the complaint points out that that calculation assumes that no one on the mail-in ballot list would show up to vote physically, even though 72,185 early voters showed up to voter in person in 2012’s general election. Furthermore the complaint alleges that officials ignored reports that the current primary was bringing increased turnout.

Maricopa didn’t think about minority communities when placing its vote centers.

Before Shelby County, Maricopa’s election plans would have had been to submitted to federal authorities who would assess them with Arizona’s history of racial discrimination in mind. Without the feds looking over their shoulders, county officials didn’t examine closely enough the racial implications of how they distributed the vote centers, the lawsuit alleged. “The reduction of voting locations was particularly burdensome on Maricopa County’s Hispanic and African-American communities, many of which had fewer polling locations than Anglo communities and, in some instances, no voting locations at all,” the complaint said.

That question came up at the public hearing Maricopa County Recorder Helen Purcell — the local elections chief — and state officials had for citizens to air their grievances after March’s botched primary, according to the complaint.

An attendee asked Purcell if she considered how the distribution of vote centers would affect minority communities, to which Purcell responded that she was looking at Maricopa as a whole and not “specific areas.”

The lawsuit points to that exchange to argue, “Ms. Purcell made no effort whatsoever to ensure that her decisions would not disparately disenfranchise minority voters in Arizona.”

For instance, the complaint said, there was a polling place for every 8,500 residents in the largely white community of Cave Creek, but in Phoenix — which is majority-minority and about 40 percent Hispanic — an average of 108,000 residents would be sharing a single polling place.

Maricopa didn’t do enough outreach to educate voters on the new voting centers.

Civil rights advocates argue that with a fully functioning Voting Rights Act, federal officials would have also vetted local officials’ voting outreach efforts, and here too, Maricopa County fell short, the lawsuit said.

According to the complaint, the County Recorder’s Office only began informing residents 12 days before the presidential primary that Maricopa was switching to a vote center system where there would be 60 locations instead of the usual 200 precincts.

Maricopa County is about to make matter worse by switching back to the old precincts system.

In hopes of preventing a repeat of the chaos of the March presidential primary, Maricopa plans on doubling its vote centers for a special election coming in May. However, for an August primary and then for November’s general election, the county will return to its precinct systems, where voters will need to show up to the specific polling place assigned to them.

County officials say this was always the plan and that vote centers won’t be possible for the August primary and the general election.

“We wish they could go everywhere and vote,” Elizabeth Bartholomew — a spokesperson for Maricopa County Recorder’s Office — told TPM. She said there are somewhere between 2,500 to 5,000 ballot styles for those elections because they also feature local races where candidates vary district by district. “It makes ballots very specific to where you live; therefore, that is why you have to go to the specific precinct,” she said.

County officials are further constrained by state law that prohibits provisional ballots cast by people who show up to the wrong precinct to be counted, Bartholomew said.

Thus, the lawsuit is asking the court to block for the general election that portion of Arizona’s law, pointing specifically to the high rate of ballots thrown out in Maricopa due to voters showing up at the wrong precinct.

A new state law criminalizing ballot collection is exacerbating the problems.

State officials are also named in the lawsuit because of a GOP-backed state law passed just this spring that criminalized a practice long used in get-out-the-vote efforts in which absentee voters can have their signed and sealed ballots physically turned in for them, rather than having to mail them in.

The law — known as HB 2023 — was not in effect for the presidential primary, but will be in place for November’s general election, so the complaint is asking for the judge to block that law as well.

“[I]t will have a disparate impact on Arizona’s Hispanic, African-American, and Native-American populations, who rely disproportionately on the collection of ballots to cast their early votes,” the complaint said. “These populations’ reliance on ballot collecting is directly connected to the long history of discrimination that they have been subject to in Arizona, which has left them with less access to transportation; less flexible work schedules; and a higher likelihood of suffering from poor health and disabilities.”

The lawsuit points to the lack of evidence produced throughout the legislative process showing that ballot collection was leading to election fraud.

“Upon information and belief, the Republican-controlled Arizona State Legislature passed H.B. 2023 with the purpose and effect of suppressing Democratic votes through the disenfranchisement and abridgement of the right to vote of minority voters in Arizona,” the lawsuit alleged.

Corrected on 4/19/2016: A previous version of this story said that the Hillary Clinton campaign had filed the lawsuit with the Democrats. Her campaign is not currently a party on the lawsuit, but is reportedly expected to join the lawsuit as the litigation proceeds. The Bernie Sanders campaign is also expected to join the lawsuit.