As a result of a wave of challenges to the 1965 Voting Rights Act, that seminal American law faces a likely review by the supreme court, whose conservative Republican majority is the most rightward-leaning in modern history. If the Voting Rights Act is toppled, other civil rights laws – including the 1964 Civil Rights Act – are in danger as well.

Faced with recalcitrant state officials who prohibited blacks from voting, and federal laws that proved inadequate in stopping them, Congress passed the Voting Rights Act. Its purpose was to outlaw the discriminatory voting schemes that disenfranchised African Americans in the south and elsewhere. For example, section 2 of the legislation banned the use of literacy tests as a voting requirement. Meanwhile, section 5 required certain jurisdictions with a history of racial discrimination to obtain federal approval for changes to its voting laws. The section applies to nine states and sections of seven other states. The act also allows the attorney general to challenge the use of poll taxes.

Passage of the legislation was expedited by acts of racial violence in the south, including the murder of three civil rights workers in Philadelphia, Mississippi in 1964, and the brutal 1965 police attack on peaceful protesters marching across the Edmund Pettus Bridge on their journey from Selma to Montgomery, Alabama.

Although the Voting Rights Act was passed by a Democratic-controlled Congress and signed by a Democratic president, most opposition came from southern Democratic lawmakers who had an interest in maintaining Jim Crow segregation and suppressing the political aspirations of African Americans. A larger majority of Republican lawmakers supported the act, as their party had supported "full implementation and faithful execution" of all civil rights statutes in its 1964 platform. After all, the "Grand Old Party" was once the party of the Radical Republicans, who had ushered in the civil rights amendments abolishing slavery, granting citizenship to blacks and allowing for black suffrage. In the post-civil war reconstruction era, the Republicans boasted some 2,000 black elected officials nationwide.

In the late 1960s, however, the Republicans began employing a "southern strategy" to capitalize on white resentment of civil rights. A color-coded politics, perfected by the late GOP operative Lee Atwater, allowed taxes, big government and welfare to become proxies for the N-word. This led to the realignment of Dixie, with the Republican party controlling the former confederate states, and blacks eventually shifting their allegiance nearly exclusively to the Democrats.

Moderate whites fled the party, as well. The more recent Tea Party takeover of the GOP – with the attendant hatred of a black president, Latino immigrants, civil rights and multicultural diversity – represents a natural consequence of that strategy. And the exclusively rightwing Republican fixation with voter fraud and voter ID reflects this new reality.

Across the nation, 33 states have proposed laws restricting voting, including a requirement that citizens present a government-issued photo ID in order to vote. Spurred by conservative Republican legislators and their American Legislative Exchange Council (Alec), these laws are promoted under the pretext of combating voter fraud. Yet, voter fraud is exceedingly rare, with a 1 in 2.3m chance of occurring in a federal election, according to the NAACP. In a lawsuit challenging Pennsylvania's draconian voter ID law, lawyers representing the Republican-controlled commonwealth conceded there is no evidence voter fraud exists.

Meanwhile, Mike Turzai, the Republican leader in the state House of Representatives, has proclaimed that voting restrictions will enable a Republican victory in the upcoming presidential election. "Voter ID, which is gonna allow Governor Romney to win the state of Pennsylvania, done," he said. The states that have enacted such laws account for 78% of the electoral votes needed to elect the president, according to the Brennan Center for Justice.

In Texas, where the state's discriminatory voter ID law was recently overturned by a federal appeals court, the state Republican party platform calls for a repeal of the Voting Rights Act. Supporters of repeal claim section 5 of the Act places an undue burden on some states and not others. And yet, the scourge of racially-motivated voter disenfranchisement legislation throughout the country, a potent example of Republican hubris and overreach, provides ample proof that the act is needed now more than ever.

America is on the path to becoming a nation whose majority consists of people of color. The ongoing attack on civil rights, funded by the Koch Brothers and others, reflects a refusal by white conservatives to accept this new reality. Latinos are the fastest growing demographic group in the south, and African Americans are participating in a reverse migration to that region of the country.

Given these circumstances, it is inevitable that red southern states will turn to blue, as Obama won North Carolina and Virginia in 2008. But amidst this demographic shift, the GOP is a nearly exclusively white party, with whites accounting for over 90% of the delegates at this year's convention in Tampa. The recent assault on a black CNN camerawoman by GOP convention attendees, and a recent poll showing zero percent black support for Mitt Romney, highlight the party's problem.

The Jim Crow segregation laws denied black people their voting rights, told them who they could not marry and where they could not eat, sit or use the bathroom. This legal regime criminalized and dehumanized an entire group of people by promulgating laws that only applied to them, with penalties including imprisonment and death. These were what Martin Luther King Jr called unjust laws – "a code that a numerical or power majority group compels a minority group to obey, but does not make binding on itself. This is difference made legal." The civil rights movement was an effort to eradicate unjust laws. And now, the Republican party is blatant in its efforts to undue the work of that movement by enacting unjust laws with a different name, but an identical purpose.

In its 2012 platform, the Republican party endorses the voter ID laws, stating: "Voter fraud is political poison. It strikes at the heart of representative government." But the real poison is the politically-inspired, extremist assault on civil rights in the US. And the real poisoners are those Republican lawmakers leading the charge.