WASHINGTON (AP) — Millions of dollars from anonymous donors are helping shape the fight over President Donald Trump's Supreme Court nominee as Republicans and Democrats undertake a bruising battle for ideological control of the nation's loftiest tribunal.

Even before Trump's announcement Monday that he had picked Brett Kavanaugh, a federal appeals court judge, advocacy groups had begun lining up for and against the nomination and said they would spend heavily to influence the outcome of what's expected to be a tumultuous confirmation process.

One of the most prominent groups on the right, the...