A former basketball player, Senator Ron Wyden (D-Ore.) has historically thrown about a basketball during meetings to "break the tension in the room." (Melina Mara/The Washington Post)

Sen. Ron Wyden is one of the Senate’s most ambitious dreamers, the prolific author of grand bipartisan plans to improve the health-care system and rewrite the tax code. He often wins fervent praise from reformers — but rarely much political support.

That may be about to change. Next month, Wyden (D-Ore.) is expected to take control of the storied Senate Finance Committee. Its current chairman, Sen. Max Baucus (D-Mont.), has been nominated to serve as U.S. ambassador to China.

So Wednesday, when Wyden unveiled his latest bill, a standing-room-only crowd of lobbyists, aides and reporters packed the Capitol Hill hearing room, hoping to learn which of Wyden’s many controversial ideas would rise to the top of his newly influential agenda.

Wyden was pleased but coy.

“The Finance Committee has one chairman at a time,” he demurred, smiling. Then he steered questions back to his current policy obsession: changing Medicare to encourage doctors to provide coordinated care and closer monitoring for seniors with multiple chronic conditions.

These are hectic days for Wyden, who turns 65 in May. He was already active in a number of policy areas where lawmakers hope to make progress now that the fever over the budget has finally broken. Then came news last month that President Obama would send Baucus to China, elevating Wyden to arguably the most powerful chairmanship in Congress, with vast jurisdiction over taxes and health policy.

“It’s pretty frenzied,” Wyden, who currently chairs the Senate energy committee, said in an interview. “It's a little bit like when [former energy committee chairman] Jeff Bingaman [D-N.M.] retired and everyone said: ‘Please announce your energy agenda.’ ”

The son of a journalist, the lanky Wyden got his start in politics by co-founding the Oregon chapter of the Grey Panthers, an advocacy group for the elderly. He served as its director for seven years. He won election to Congress in 1980 at the age of 31 and ascended to the Senate in 1996 to fill the seat vacated by Bob Packwood (R), who resigned amid allegations of sexual harassment.

In the Senate, Wyden quickly gained a reputation for collaborating with Republicans to solve knotty national problems. He and former senator Robert F. Bennett (R-Utah) drafted an overhaul of the health-insurance system long before Obama was elected. Wyden also drafted, with former senator Judd Gregg (R-N.H.), a comprehensive rewrite of the federal tax code that aimed to wipe out dozens of tax breaks and deductions while lowering overall rates.

Wyden “is a creative thinker who doesn’t march to a liberal drummer,” Gregg said. “He thinks outside his own ideological box.”

Wyden’s iconoclasm has at times gotten him into hot water with fellow Democrats. In 2011, for example, he teamed up with House Budget Committee chairman Paul Ryan (R-Wis.) on a plan to transform Medicare.

Wyden insisted that the proposal would have preserved the Medicare coverage guarantee and softened Ryan’s controversial plan to save money by capping per-person spending. But Democrats were furious, especially after Ryan joined the 2012 GOP presidential ticket and Mitt Romney began referring to Ryan’s “bipartisan” Medicare proposal.

Wyden has since backed away from his work with Ryan, and at Wednesday’s news conference took another step in that direction. After bitter political battles over Medicare in 2010 and 2012, Wyden said he is looking to wipe the slate clean and come up with new ideas that represent a “fresh start.”

“Much of the Medicare debate is: Are you going to cut people’s benefits? Or are you going to stand pat?” Wyden said. “This gets out of that debate.”

The chronic-care proposal is vintage Wyden: far-reaching and based on the best available research. Given that the 14 percent of Medicare patients who have six or more chronic conditions account for 70 percent of program spending, the proposal might even save money.

Dubbed “The Better Care, Lower Cost Act of 2014,” the proposal has a ready pool of learned enthusiasts, many of them doctors and insurance executives who showed up at Wednesday’s news conference. Wyden’s co-sponsors were there as well: from the Senate, Johnny Isakson (R-Ga.), and from the House, liberal Peter Welch (D-Vt.) and conservative Erik Paulsen (R-Minn.).

“I said, yes, absolutely,” when Wyden called, Paulsen said. “I was excited about working on something that was results-oriented, if you will. And Wyden has a good reputation for that — for working bipartisanly, for being able to move things forward. Especially things that are big things.”

As he forges ahead on Medicare, Wyden is also expected to pursue tax reform, a top priority not only for Baucus but also for his House counterpart, Ways and Means Chairman Dave Camp (R-Mich.) and for Ryan, a likely future Ways and Means chairman .

In a statement, Ryan called Wyden “a man of principle” who “understands that true bipartisanship builds on the best ideas from both parties. I am proud of my work with him to preserve the Medicare guarantee.”

Wyden seems to be approaching the massive agenda with patience and a surprising degree of pragmatism. He is, for example, supporting a push by Senate Majority Leader Harry M. Reid (D-Nev.) to revive a package of tax breaks that expired Dec. 31, including a popular tax credit for research and development and provisions for renewable energy and electric vehicles.

Camp opposes action on the package, preferring to use the expired tax breaks as leverage to advance tax reform.

Wyden said addressing them as part of a fundamental overhaul would be “my first choice” as well. But there is a distinct lack of support in Congress for rewriting the tax code months before this year’s midterm elections. Given that reality, Wyden said Wednesday, “I’m not going to sit idly by while plans for renewable energy development are sacrificed on the altar of inaction.”