WASHINGTON — On the cusp of a key legislative push, President Barack Obama on Monday filled the Rose Garden with doctors supportive of his health care overhaul, saying “nobody has more credibility with the American people on this issue than you do.”

Dr. Richard A. Evans, one of Maine’s two delegates to the American Medical Association and a general surgeon from Dover-Foxcroft, was among them. He has visited Washington several times and is a familiar face to Maine’s congressional delegation.

“It put things in perspective,” Evans said during a telephone interview Monday. “If you are standing in the Oval Office and have the president talking face to face with you, recognizing that there are problems that need to be faced and you are all on the same page, then the reality really sets in.”

Obama’s White House event gave the president another chance to frame the debate on his terms as his top domestic priority enters its most critical phase with legislation moving toward floor debates in the Senate and the House.

The Senate Finance Committee is expected to clear its long-debated, intensely scrutinized bill this week. Sen. Debbie Stabenow, D-Mich., said a vote originally expected by Tuesday has been pushed back, because the Congressional Budget Office is still crunching cost and coverage numbers.

The latest version of the Finance bill will cover fewer people after senators last week softened penalties for not carrying health insurance. Stabenow said she expects it will cover 92 percent or 93 percent of Americans, down from about 95 percent in earlier versions. The penalties were reduced because there’s not enough money in the $900 billion, 10-year bill to provide subsidies for all middle-class households.

White House budget director Peter Orszag acknowledged the tension between keeping down costs and the goal of providing coverage for all.

“There’s no doubt there’s a trade-off,” he told reporters and editors from The Associated Press in an interview Monday.

After the Finance Committee finishes its work, Senate Democratic leaders will meld it with a more liberal-leaning version passed by the Health, Education, Labor and Pensions Committee. The House also must combine differing versions of its own bills before opening floor debate.

Republican opposition to the Democratic-crafted bills has been almost unanimous thus far in Congress, but a few former GOP officials have had kinder things to say about them.

Tommy Thompson, a 2008 presidential candidate who headed the Health and Human Services Department under President George W. Bush, said Monday the Finance Committee bill “is another important step toward achieving the goal of health care reform this year.”

Bill Frist, a heart surgeon and former Senate Republican leader, told Time magazine he would vote for the Finance bill if he were still in Congress. Both Frist and Thompson said the bill could be improved by amendments, however.

As a visual plug for Obama’s efforts, the White House arranged Monday for the president to have some 150 doctors representing all 50 states arrayed in the sun-splashed lawn area just outside the West Wing. To make sure no one watching at home or catching news footage later would miss the point, the physicians wore their white lab coats.

“When you cut through all the noise and all the distractions that are out there, I think what’s most telling is that some of the people who are most supportive of reform are the very medical professionals who know the health care system best,” said Obama, flanked by four doctors on stage for good measure.

Evans of Dover-Foxcroft, who was one of the four, said he supports the president’s initiative not because he sees it as a panacea, but because it promises to address problems that for Evans have gone unaddressed for far too long.

“Every time you have an election, the public always demands health care reform,” Evans said, “but when it comes down to actually doing it, people step back. You can only do that so long.”

Obama’s initiative Evans hopes will stem the rising cost of health care, costs that absorbed an estimated 16 percent of gross domestic product and are expected to absorb 25 percent by the year 2025.

It should be particularly beneficial to Maine’s small businesses, which paid an average cost of employee health care benefits of $12,600 in health insurance premiums in 2008 and $13,500 so far in 2009 — a 120 percent increase, Evans said.

About one in three residents pays $1,000 in out-of-pocket health expenses, Evans said. Such exorbitant costs, which he blames on health insurers, lead to more emergency room visits for people who don’t get adequate preventive care, a “hidden tax” on the public, Evans said.

“As a physician and surgeon, I see how the lack of health care affects people,” Evans said. “For people who don’t get the routine or preventative care that they need, morbidity will be so much higher. Uncontrolled blood pressure becomes diabetes because they don’t get the same, routine follow-ups [doctor care] that other people with insurance get.

“These are things that happen every day and it’s just getting worse,” Evans said. “We have talked this to death. It’s time to do something about it.”

But Sen. John Barrasso, R-Wyo., an orthopedic surgeon for 25 years, said many doctors, nurses and patients strongly oppose Obama’s proposals.

They are greatly alarmed at proposed cuts in Medicare, which is the main source of health care for many people in Wyoming and elsewhere, Barrasso said in an interview Monday. He said doctors and hospitals also want provisions to protect them against “abusive lawsuits” by people claiming malpractice.

Obama broke no ground in his comments. He outlined the tenets of his health reform plan: expanded and affordable health coverage options for tens of millions of people, strengthened protections for those who already have insurance, and more time for health professionals to help patients with preventive and healing care.

Obama said the country has heard all sides of the debate over the last few months and the time to act is now.

“I want to thank every single doctor who is here,” Obama said. “And I especially want to thank you for agreeing to fan out across the country and make the case about why this reform effort is so desperately needed. You are the people who know this system best. You are the experts.”

Bangor Daily News writer Nick Sambides Jr. and Associated Press writers Ken Thomas and Ben Feller contributed to this report.