There is indirect discrimination at the ballot box. According to the American Civil Liberties Union (ACLU):

Some states … discourag[e] voter participation by imposing arbitrary requirements and harsh penalties on voters and poll workers who violate these rules. In Georgia, lawmakers have made it a crime to provide food and water to voters standing in line at the polls — lines that are notoriously long in Georgia, especially for communities of color. In Texas, people have been arrested and given outrageous sentences for what amount at most to innocent mistakes made during the voting process. ACLU clients Crystal Mason and Hervis Rogers are examples [see below] ….

Because of racism in law enforcement and the broader criminal legal system, criminalization of the ballot box disproportionately impacts people of color, who are more likely to be penalized. This method of voter suppression aims to instill fear in communities of color and suppress their voices in the democratic process.

Mason, above, ‘was criminally prosecuted and sentenced to five years in prison for allegedly casting a provisional ballot improperly.’ The case, appears to be awaiting appeal, several years later. This likely would not happen at all to a white voter:

… [A] case involving former Republican U.S. Congressperson Tom DeLay, DeLay v. State, in which the court of criminal appeals threw out his conviction on the basis that an individual must actually know that their conduct violates the election code.

In addition to being criminalised at the polling station, black people are more likely to be criminalised in general, which in some states means there is no point in going to vote at all. Disproportionate racial criminalisation is not new. The Growth, Scope, and Spatial Distribution of People With Felony Records in the United States, 1948–2010:

We estimate that 3 % of the total U.S. adult population and 15 % of the African American adult male population has ever been to prison; people with felony convictions account for 8 % of all adults and 33 % of the African American adult male population.…

Contact with the criminal justice system incurs substantial social and demographic consequences, including restrictions … voting ….

[A]lmost one-half of all black men will be arrested prior to the age of 23. … People with any kind of criminal history experience wide-ranging penalties and disruptions in their lives …. Nevertheless, people convicted of felonies face more substantial and frequently permanent consequences …. A felony is a broad categorization, encompassing everything from marijuana possession to homicide. …

Recent estimates have shown that 30 % of black males have been arrested by age 18 (vs. 22 % for white males) …. This figure grows to 49 % by age 23, meaning that virtually one-half of all black men have been arrested at least once by the time they reach young adulthood (vs. approximately 38 % of white males) ….

[A] dramatically higher percentage of African American adults in most states were under felony correctional supervision. … [B]y 2010, the rate exceeded 5 % of African American adults in 24 states, and no state had less than 2.5 % of its adult African American population under supervision for felony convictions. States such as Oregon, Rhode Island, and Wisconsin had rates exceeding 8 %.

The Hervis Rogers case, mentioned in the ACLU report, above, illustrates the problem:

… Rogers was arrested on charges that he voted in last year’s Democratic primary while on parole. Under Texas law, it is illegal for a felon to “knowingly” vote while still serving a sentence, including parole. Doing so is a second-degree felony, punishable with a minimum of two years and a maximum of 20 years in prison. In at least 20 states, Rogers’s alleged vote would not be a crime.

The label ‘felon’ can inaccurately invoke the image of a dangerous criminal:

“You know, this guy thought he could vote,” said state Sen. Borris Miles of Houston, who held up a printed photo of Rogers in a Senate committee hearing on the legislation. “He was under the belief in his mind that he really could. Served his time, got a nice job, nice family, now, thought he could vote, just thought he was doing his civic duty.”

The result is racial ‘felony disenfranchisement’:

A felony conviction can … includ[e] the loss of your right to vote. Some states ban voting only during incarceration, or while on probation or parole. And other states and jurisdictions, like Maine, Vermont, and Washington, D.C., don’t disenfranchise people with felony convictions at all. The fact that these laws vary so dramatically only adds to the overall confusion that voters face, which is a form of voter suppression in itself.

… [F]elony disenfranchisement laws disproportionately affect Black and Brown people, who often face harsher sentences than white people for the same offenses. …

In 2016, black Americans comprised 27% of all individuals arrested in the United States—double their share of the total population. Black youth accounted for 15% of all U.S. children yet made up 35% of juvenile arrests in that year. What might appear at first to be a linkage between race and crime is in large part a function of concentrated urban poverty.…

The rise of mass incarceration begins with disproportionate levels of police contact with African Americans. This is striking in particular for drug offenses…. As black people are presumed to be more likely to have committed crimes than white people, police target black communities (a legacy of segregation): [One] chief [said]: “Crime is often significantly higher in minority neighborhoods than elsewhere. And that is where we allocate our resources.” Dekmar’s view is not uncommon. … U.S. criminal justice policies have cast a dragnet targeting African Americans. The War on Drugs as well as policing policies … sanction higher levels of police contact with African Americans. This includes higher levels of police contact with innocent people and higher levels of arrests for drug crimes. Thus:

• More than one in four people arrested for drug law violations in 2015 was black …[.] [B]lacks were 3.7 times more likely to be arrested for marijuana possession than whites in 2010, even though their rate of marijuana usage was comparable.

• New York City … Between 2001 and 2013, 51% of the city’s population over age 16 was black or Hispanic. Yet during that period, 82% of those arrested for misdemeanors were black or Hispanic, as were 81% of those who received summonses for violations of the administrative code (including such behaviors as public consumption of alcohol, disorderly conduct, and bicycling on the sidewalk.). …

In addition … policymakers and criminal justice leaders have been late to address discriminatory policies …—such as biased use of officer discretion …. Thus:

• In recent years, black drivers have been somewhat more likely to be stopped than whites but have been far more likely to be searched and arrested. … [S]taggering racial disparities in rates of police stops persist in certain jurisdictions—pointing to unchecked racial bias …[. P]olice are more likely to stop black and Hispanic drivers for discretionary reasons—for “investigatory stops” (proactive stops used to investigate drivers deemed suspicious) rather than “traffic-safety stops” (reactive stops used to enforce traffic laws or vehicle codes). … Once pulled over, black and Hispanic drivers were three times as likely as whites to be searched (6% and 7% versus 2%) and blacks were twice as likely as whites to be arrested.

All this amounts to substantial voter disenfranchisement, 20% of black people are unable to vote in some states:

Disenfranchisement patterns have also reflected the dramatic growth and disproportionate impact of criminal convictions. A record 6.1 million Americans were forbidden from voting because of their felony record in 2016, rising from 1.2 million in 1976. Felony disenfranchisement rates for voting-age African Americans reached 7.4% in 2016—four times the rate of non-African Americans (1.8%). In three states, more than one in five voting-age African Americans is disenfranchised: Florida, Kentucky, and Tennessee.

This has little to do with actual criminality:

The majority of disenfranchised Americans are living in their communities, having fully completed their sentences or remaining supervised while on probation or parole.

There are further issues with the requirement for voter ID:

… strict ID laws are part of an ongoing strategy to suppress the vote. Over 21 million U.S. citizens do not have qualifying government-issued photo identification, and these individuals are disproportionately voters of color. That’s because ID cards aren’t always accessible for everyone.

Overall:

• Across the country, 1 in 16 Black Americans cannot vote due to disenfranchisement laws. …
• 25 percent of voting-age Black Americans do not have a government-issued photo ID. …

When it comes to the other side of the vote, receiving enough votes to hold office, black mayors may be refused entry to the Town Hall by the white establishment.

For several other links on this subject, see: The Impact of Voter Suppression on Communities of Color