Texas Elections 2018 More in this series

*Editor's note: This story has been updated throughout.

Texas Attorney General Ken Paxton is getting his first Democratic opponent for re-election.

Attorney Justin Nelson is entering the race to be the state's top lawyer with just over a month until the candidate filing deadline for the 2018 primaries.

"Justice is for all. Nobody is above the law," Nelson said in a news release. "Texans can do better than our indicted Attorney General who is charged with criminal fraud."

Paxton, who is seeking a second term, has been under indictment for most of his current term, fighting securities fraud charges stemming from allegations before his time as attorney general. Those legal troubles have made him a top target for Democrats in 2018, despite the void of challengers until now.

Nelson, 42, is a partner specializing in major civil litigation at the Houston law firm Susman Godfrey LLP and has been named a Texas Super Lawyer by Thomson Reuters. A graduate of Yale University and Columbia Law School, he clerked for former U.S. Supreme Court Justice Sandra Day O'Connor and for Harvie Wilkinson, a judge on the U.S. Court of Appeals for the 4th Circuit.

Nelson lives in Austin, where he is an adjunct professor at the University of Texas School of Law.

Nelson is not entirely new to politics. He is the founder and former president of One Nation One Vote, a group that is pushing to elect the president by popular vote. The issue has been a hot topic in the wake of the 2016 election, when Donald Trump beat Hillary Clinton in the Electoral College but lost to her in the popular vote.

Paxton's campaign declined to comment on Nelson's candidacy.

Nelson is joining the race as Democrats scramble to fill out their statewide ticket with serious contenders, most notably for the gubernatorial contest. The candidate filing period begins Saturday and concludes a month later.

Upon Nelson's announcement, another Democrat who had been mulling a run for attorney general, Lubbock attorney John Gibson, threw his support to Nelson.

"I am honored by the outpouring of support I have received but I have decided that Justin and I are so similar in vision that it makes no sense for both of us to run," Gibson said in a statement. "Justin Nelson is the best person to defeat Ken Paxton and restore integrity to the office of Attorney General."

Nelson still may not be the only Democrat vying to challenge Paxton in March. Vincent Harding, the outgoing chairman of the Travis County Democratic Party, has said he is weighing a run as well.

"I have known Justin for several years and wish him the best," Harding said in a statement after Nelson's announcement. "As previously mentioned, there are a few factors that will impact whether I accept requests to run for Attorney General. My interest in elected office is to help usher in a new kind of politics based on people and principle over power and money. I will make a decision on whether to run for AG by the first week in December, if not sooner."

Paxton's legal saga is likely to continue well into the 2018 race. He is currently waiting for a new trial date in the state's long-running criminal case against him, which goes back over two years. The trial has been delayed three times, most recently due to the prosecutors' push to put it off until they can get paid. After prosecutors won the latest delay, Paxton's lawyers suggested rescheduling the trial for March.

Paxton has pleaded not guilty to all the allegations. He has already been cleared in a similar civil case at the federal level.

Alex Samuels contributed reporting.

Disclosure: The University of Texas at Austin has been a financial supporter of The Texas Tribune. A complete list of Tribune donors and sponsors is available here.