Steve A. Matthews spent more than 509 days as a judicial nominee, waiting to see what it would be like to be a judge on the U.S. Court of Appeals for the 4th Circuit. He never found out.

Sen. Patrick Leahy, the Vermont Democrat who chaired the Senate Judiciary Committee during the end of President George W. Bush’s second term, refused to schedule a hearing on Mr. Matthews, and his nomination expired when Mr. Bush left office in 2009.

Now, as many of President Trump’s nominees for posts on the courts and in the executive branch await action, Mr. Matthews says something needs to change.

“It really is a disservice to ask someone to undertake public service and say, ‘Oh, by the way, for the next one to 24 months we are going to disrupt your private career while we decide,’” Mr. Matthews told The Washington Times.

For Mr. Matthews, he didn’t have to put off his current workload because he was working as his firm’s managing partner for much of that time, and he wasn’t involved in active cases.

But for others, the wait can be a major shakeup.

Appeals court Judge Merrick Garland, nominated to the Supreme Court by President Obama, stopped hearing cases during the 10 months he spent waiting for action by the GOP-led Senate. He never got a hearing or a vote.

Lawyers nominated for court posts sometimes have to limit the number of cases they take on, and some potential clients may avoid them because of their unknown future.

Carrie Severino, chief counsel at the conservative Judicial Crisis Network, said law professors who are nominated to the federal bench face a different set of issues. They have to decide how many classes they can commit to teaching and whether to continue writing scholarly articles, which often give senators fuel for questioning during confirmation hearings.

“Publishing also would be a question,” Ms. Severino said. “You would presumably lay low and not publish.”

Mr. Trump has 59 judicial nominees awaiting to be confirmed by the Senate or for the Judiciary Committee to take up their nominations.

Michael B. Brennan, tapped for the U.S. Court of Appeals for the 7th Circuit, was nominated more than 216 days ago, making him the longest pending appellate court pick.

Claria Horn Boom, nominated to the Eastern and Western Districts of Kentucky, is the longest pending district court nominee — at more than 265 days.

Marge Baker, executive vice president at the liberal People For the American Way, said Mr. Trump has had more judicial nominees get confirmed during his first 14 months in office than Mr. Obama. She said Mr. Trump’s judicial nominees have waited only an average of 125 days before being cleared by the Senate, versus Mr. Obama’s nominees who waited an average of 261 days.

“What we are talking about now, the so called delays [] just pale in comparison,” Ms. Baker said.

Senate rules place no limits on how long a nominee can wait.

The average circuit judge waited about 55 days between nomination and confirmation under President Reagan. That stretched to nearly 200 days under President Clinton, and topped out at more than 365 days under Mr. Bush, according to numbers from the Congressional Research Service. Circuit judge waiting times ticked down during Mr. Obama’s first six years, but district judge wait times rose.

Not everyone gives up on work during the wait. Judge Joan Larsen continued to hear cases on the Michigan Supreme Court while awaiting confirmation to the U.S. Court of Appeals for the 6th Circuit. The Senate confirmed her in November, after a wait of 176 days.

Curt Levey, president of the Committee for Justice, said it’s a nerve-racking experience for nominees, who must wait for updates from the White House about their nominations because they aren’t allowed to approach the Senate to find out what’s next for them.

“What these people go through personally is sort of not known partly because it gets caught up in a political battle, and at the end of the day, probably not a lot of the politicians fighting over it care about the personal impact,” Mr. Levey said.

Both parties have engaged in delaying tactics — and have complained when the other side has done it.

Mr. Leahy, who blocked action on Mr. Matthews a decade ago, expressed no regrets about that — but blasted the GOP for its delay on Judge Garland, who set a new record for wait by a Supreme Court nominee.

“Chief Judge Garland was a highly respected nominee who was universally recognized as well qualified and within the mainstream. The decision to deny him a hearing or a vote in 2016 for his Supreme Court nomination was done solely and cynically to manipulate the makeup of the Supreme Court,” said David Carle, a spokesman for the senator. “By contrast, Mr. Matthews had exhibited views outside the mainstream of legal jurisprudence.”

Republicans brushed off Mr. Leahy’s reference to Judge Garland, and wouldn’t comment about the difference in delays between him and Trump nominees.