WASHINGTON (CNN) -- Hillary Clinton stands ready to take up the fight for voting rights as she takes the stage in Texas on Thursday.

The issue -- far from the spotlight when she last ran in 2008 -- has taken on far greater importance in the wake of GOP-passed laws in recent years they say are aimed at reducing voter fraud, but Democrats say depress voter turnout. Democrats argue stringent voting laws -- limit early voting opportunities or require ID to register to vote -- most affect the poor, who may not have a valid ID, and those who can't take off work to head to the polls.

What's more, the Supreme Court ruled in 2013 that a key aspect of President Lyndon Johnson's Voting Rights Act of 1965 was no longer constitutional.

The changes have drawn Democrats -- including lawyers close to Clinton and the Democratic National Committee -- into a voting rights fight that some African-Americans, like South Carolina Democrat Bakari Sellers, are calling "the greatest challenge of our generation."

Clinton will push for "swift action" on the issue and knock Republicans for supporting voting laws that she says keep people away from the ballot box.

The comments will come during a speech at Texas Southern University, a historically black college, after Clinton receives an award named after Barbara Jordan, a pioneer African-American lawmaker and civil rights leader.

Clinton, an aide said Wednesday, will call for "a new national standard of no fewer than 20 days of early in-person voting in every state, including weekend and evening voting" during the speech.

Clinton will "draw a sharp contrast with Republicans who have fought to curb early voting," the aide said. In particular, she will target efforts in North Carolina, Texas, Wisconsin and Florida.

The former first lady has long been a supporter of voting rights: She helped register voters in Texas' Rio Grande Valley during the George McGovern's failed 1972 presidential run. But supporting voting rights now has the added benefit of helping keep together the coalition of voters that elected and re-elected President Barack Obama.

Obama won 93% of African-American voters in 2012 and 95% in 2008, according to exit polls. Some Democrats worry that Clinton needs a similar performance with African-American voters and disenfranchisement is an issue that Democrats hope will activate that base.

The first few months of Clinton's campaign have seen a number of events and trips focused on African-American voters.

In her first speech as a candidate, Clinton called for mandatory police body cameras across the country and end "era of mass incarceration," an issue that connected with African-American activists concerned about black men dying at the hands of law enforcement.

Clinton also focused on a minority-owned business in her first trip to South Carolina, a state with a sizable African-American population that overwhelmingly picked Obama over her in the 2008 primary.

"Secretary Clinton is addressing the right issue in the right place at the right time," Cornell William Brooks, president and CEO of the National Association for the Advancement of Colored People, told CNN on Wednesday.

"It is our hope that she and presidential contenders on both sides of the aisle will not only address the issue but support fixing the badly broken Voting Rights Act," the NAACP president said, arguing that anyone not "well versed and strongly positioned in our nation's voting and criminal justice rights challenges" will likely not be "deemed by a majority of the electorate as deserving to hold the office."

Clinton's top campaign lawyer, Marc Elias, has also taken on the fight by filing lawsuits challenging voter restriction laws in Ohio and Wisconsin. He told The New York Times on Wednesday that, "We should all want to ensure that all eligible voters can exercise their right to vote and have their vote counted."

Supporting voting rights was one of the first issues the former secretary of state dove head first into shortly after leaving the State Department with a speech at the American Bar Association's annual meeting in San Francisco in August 2013.

Clinton condemned voter ID laws, telling the audience of lawyers that they are bringing back the "old demons of discrimination."

"We do, let's admit it, have a long history of shutting people out: African-Americans, women, gays and lesbians, people with disabilities," Clinton said. "And throughout our history, we have found too many ways to divide and exclude people from their ownership of the law and protection from the law."

Rhetoric like that, according to Sellers, was welcome to many in the African-American community.

"This message whether it is her speech on immigration, whether or not it is her speech on police reform, it has to be heard in the barber shops, not just by the pastors, but by their congregations," Sellers said. "It has to reverberate."

™ & © 2015 Cable News Network, Inc., a Time Warner Company. All rights reserved.