Days before the Iowa caucus formally kicks off an increasingly tight race for Democratic presidential nomination, U.S. Sen. Ron Wyden said Saturday he was finally ready to reveal his pick: Hillary Clinton.

The endorsement from Oregon's senior senator isn't all that surprising. Wyden has previously said he generally supported and liked Clinton -- a former secretary of state and U.S. senator from New York -- but always stopped short of making things official, saying the time wasn't right.

Now that voting is about to start, Wyden said, things have changed. He explained his rationale in a phone interview from Medford, where he appeared at an event for Planned Parenthood.

"The last few years, a number of new forces have emerged in American politics," he said, "forces that deny science, forces that believe constitutional protections are only for their own beliefs, forces that reject bipartisanship in the name of ideology.

"Secretary Clinton, as president, has the passion and the energy and the skills to push back on those developments and offer an alternative."

Wyden also said the timing of his announcement, coming as he shows public support for Planned Parenthood, wasn't coincidence. He said Clinton has supported women's issues and reproductive rights since coming to Washington, D.C., in 1993 as first lady. That work, he said, continued as they worked alongside each other in the Senate.

"Planned Parenthood, particularly the family planning work they do, is one of the best strategies to reduce abortions," he said. "She's been in the vanguard of those issues."

Clinton's pursuit of the nomination eight years after losing to President Barack Obama's upstart campaign has been complicated in similar fashion by the emergence of Vermont Sen. Bernie Sanders.

Sanders, who has drawn throngs in stops around the country, including Portalnd, and collected record amounts of individual ampaign donations, has hung around as a populist challenger on Clinton's left.

Polling in recent weeks has shown Sanders and his messaging on economic inequality pulling ahead of Clinton in both Iowa and New Hampshire, which will hold the first primary election in the 2016 election Feb. 9.

Wyden didn't say much about Sanders but said his pick shouldn't be seen as "putting a knock on anybody."

Sanders and Wyden have lined up on certain issues. Sanders was one of two senators who joined Wyden in voting against a bill last year that increased defense spending. (Sen. Jeff Merkley, D-Ore., was the other.)

Wyden, a senior member of the Senate's intelligence committee, also played down a resurgence of headlines this week over Clinton's use of an unsecured home email server when she was secretary of state. Nearly two-dozen emails among thousands were found to have been "top secret."

"Sen. Sanders was right a while back when he said enough with the emails," Wyden said.

He called the government's system for classifying confidential emails "dysfunctional," with emails and other information, he argues, often classified needlessly.

"Having served on intelligence committee for many years, there's absolutely no rhyme or reason to the classification system."

Wyden said he expects a lengthy primary contest. But he wouldn't guess whether it might remain competitive until May, when Oregon voters weigh in on Clinton vs. Sanders and also on whether Wyden himself should receive his party's nomination for another term.

"We'll have to see," he said. "The presidential primary is going to go on a while."

-- Denis C. Theriault

503-221-8430; @TheriaultPDX