DETROIT (AP) — Labor unions and worker advocates have applauded President Joe Biden's nomination of Judge Ketanji Brown Jackson for the Supreme Court. Yet a look back at Jackson's decisions in cases involving business and labor suggest that she won't always rule as they want or expect her to.

Though Jackson is widely seen as a liberal on social and economic issues and as a defender of workers' rights, her decisions, as a federal district court judge and then as a federal appellate judge since last year, defy easy categorization.

"She's as likely to rule for a corporation in a race discrimination claim as she is for the plaintiff," said Ted Ruger, dean of the University of Pennsylvania Carey Law School, who served with Jackson on the Harvard Law Review during law school. "Like any judge who follows the law and listens to the evidence in the case, she may disappoint some who always want a predictably liberal outcome."

Out of 40 employment and business-related rulings reviewed by The Associated Press, Jackson ruled for the defendants 30 times since 2013 while serving as a judge on the U.S. District Court in Washington. Many of the cases involved discrimination claims that employees had filed against government agencies. And they hinged largely on interpretations of arcane provisions of employment laws.

In one of her private-sector cases, Jackson ruled that a Lyft ride-sharing driver had agreed to the company's terms of service when she signed up with the company, and therefore had to pursue arbitration to settle a dispute, rather than a class-action lawsuit. The driver had claimed that she and others were Lyft employees who were protected by a law in the District of Columbia that entitled them to paid sick leave.

In the view of Ruger, Jackson tends to closely follow procedural law, even when doing so might erect barriers for employees who want to make claims against companies or governments.

In one representative case from 2017, two Black employees of Lockheed Martin had alleged racial discrimination in the company's performance appraisal system. The employees asked Jackson to certify a class-action lawsuit against the defense contractor on behalf of themselves and roughly 5,500 salaried Black employees.

Jackson declined. In her ruling, which relied heavily on a 2011 Supreme Court decision that rejected a class action against Walmart, Jackson found that the employees had failed to explain how the company's performance appraisal system discriminated against Black workers. She concluded that they also failed to prove that the performance appraisal system discriminated against Black workers in the same way — a standard that would be required for a class action.

"Two anecdotes in a class of over 5,500 almost certainly do not constitute 'substantial proof' that any commonalities between them are pervasive throughout the class," Jackson wrote.

Yet the ruling wasn't exactly a victory for Lockheed Martin. Jackson questioned the adequacy of the company's proposed $22.8 million settlement fund, saying it was unclear exactly what claims other employees might bring against the company. The judge also noted that class members who didn't respond to the settlement notice — not just those who opted out — would be ineligible to receive compensation from the fund.

"This settlement agreement," Jackson wrote, "effectively allows Lockheed to inoculate itself against any and all race discrimination and race-related benefits claims by a huge swath of its African-American employees for a price that hardly seems adequate."

The two employees eventually reached a settlement agreement with Lockheed Martin.

Lia Epperson, a constitutional law professor at American University's Washington College of Law, noted that much of the work done by a U.S. District Court judge for the District of Columbia involves cases against the government, and she said Jackson showed fairness to administrations of both parties. In different criminal cases, Epperson suggested, Jackson has ruled for both prosecutors and defendants.

"She has a reputation of fairness and impartiality, and she seems to be guided by fidelity to fact and law," said Epperson, who knows Jackson from the years when they crossed paths as Harvard undergraduates.

In her first opinion as a federal appeals court judge, a position to which Jackson was confirmed last year, she ruled against President Donald Trump in a case praised by labor unions.

In 2019, the U.S. education and agriculture departments had asked the Federal Labor Relations Authority, which oversees federal labor agreements, to adopt a new threshold for when collective bargaining would be required. In September 2020, the authority required bargaining only if a workplace change had a "substantial impact on a condition of employment."

Employee unions sued, saying the new standard diminished their bargaining rights. Since the mid-1980s, the labor authority had required bargaining in cases where there had been more than a minimal change in working conditions.

In a victory for the unions, Jackson ruled that the decision to override 35 years of precedent was "arbitrary and capricious." She also questioned whether the change would solve the problems the agency had claimed it was trying to fix.

"As a former public defender, she has deep experience representing people who are too often denied access to equal justice, a perspective that has been missing from the Supreme Court since Justice Thurgood Marshall retired 30 years ago," Mary Kay Henry, president of the Service Employees International Union, the nation's second-largest labor union.

But Curt Levey, president of the Committee for Justice, a Washington group that promotes conservative judicial nominees and limited government, argued that the case was an example of Jackson having reflexively ruled against the Trump administration. When Levey studied her record before she was confirmed for the appellate court, he said, "she seemed hostile to the Trump administration."

Her ruling in the case, Levey said, applied the Administrative Procedures Act in a way that was "less deferential to the administration" than what the Supreme Court has specified in previous cases.

Refusing to certify the class of plaintiffs in the Lockheed Martin case, though, Levey said, could be a "good sign that perhaps she is not an ideologue in general."