WASHINGTON — At the age of 97, Judge Pauline Newman is the oldest full-time federal judge on the bench, but despite concerns about her ability to do the job, her colleagues are struggling to get rid of her.

For more than a year, she has been locked in a legal battle with her fellow judges on the Washington, D.C.-based U.S. Court of Appeals for the Federal Circuit, who have tried to pressure her to step aside. Newman fought back and is still contesting a decision that bars her from hearing…