He said only a fraction — he estimated 12 percent — of Russians are currently European-oriented, but he hoped to convince many of the rest that they should be, too.

“I see that I might be able to offer myself to the European-oriented part of the population as its political representative,” he said. “I don’t know whether it will work out or not, but I’m going to give it a try.”

He expressed some hesitance about the idea of becoming Russia’s leader himself. “I really hope they find somebody else,” he said. “Historically, the person in charge during the transition period most likely ends up in jail.”

Then he added with a laugh, “I’ve had enough.”

The idea may be fanciful anyway. Oligarchs like Mr. Khodorkovsky, much less those with Jewish roots, have never been especially popular in Russia, where they are blamed for fleecing the state of assets before Mr. Putin’s rise.

Moreover, Mr. Khodorkovsky has not dared to return to Russia since his release. Nezavisimaya Gazeta, a Russian newspaper, wrote after his latest announcement that “the most famous political refugee risks gaining the image of an enemy of the country.”

But his supporters said he should not be underestimated. And those he met in Washington were struck by his resolve. “I have to say I’m impressed by him,” said David J. Kramer, the president of Freedom House, which promotes democracy and human rights around the world. “But he’s still figuring out how he can make a difference. And it’s obviously very difficult to do from outside the country.”

He arrived in Washington with some of the same entourage he has had for many years, including his lawyers, Anton Drel and Maria Logan, and his longtime translator. His son, Pavel, 29, who was living in the United States when his father was arrested and later founded a group of his own to push for civil society in Russia, sat at his table at the Freedom House dinner.