Glenside, Pennsylvania (CNN) -- President Obama on Monday tore into private health insurers for recent rate hikes, taking a more aggressive rhetorical turn as he pushes for final congressional passage of his top domestic priority.

Obama repeated his assertion that the plan under consideration includes the best Democratic and Republican ideas. The time for debate has ended, he argued.

Congress "owes the American people a final up or down vote on health care. It's time to make a decision," he told an enthusiastic crowd at Arcadia University near Philadelphia. "Stand with me and fight with me. ... Let's seize reform. It's within our grasp."

The administration is ramping up its health care push in the coming weeks. The White House has called for legislation to be on the president's desk at the end of March before the congressional Easter vacation.

Two Democratic leadership aides told CNN last week that House Speaker Nancy Pelosi, D-California, is aiming to have the House of Representatives pass the Senate's health care bill by March 17.

A separate package of changes designed in part to make the overall measure more palatable to House liberals then would be approved by both chambers through a legislative maneuver known as reconciliation. Bills passed under reconciliation require a Senate majority of 51 votes. Democrats lost their filibuster-proof, 60-seat Senate supermajority with the January election of Sen. Scott Brown, R-Massachusetts.

Obama opened his remarks Monday by targeting Anthem Blue Cross in California for recently boosting its rates by almost 40 percent.

A diabetic Philadelphia-area woman introduced the president. Her insurer reportedly told her in January that her rates would more than double.

"The price of health care is one of the most punishing costs for families, businesses and our government," Obama said. "The insurance companies continue to ration health care. ... That's the status quo in America, and it's a status quo that's unsustainable."

Insurance companies, the president argued, have made a calculation. He cited a recent Goldman Sachs conference call in which an insurance broker told investors that insurers are willing to lose some customers through premium hikes because of an overall lack of competition in the industry.

"They will keep doing this for as long as they can get away with it," Obama said. "How much higher do premiums have to rise until we do something about it? How many more Americans have to lose their health insurance? How many more businesses have to drop coverage?"

Obama dismissed GOP criticism that his nearly $1 trillion proposal fails to control spiraling medical costs.

"You had 10 years," Obama said in reference to GOP control of Congress. "What were you doing?"

He also brushed aside warnings by political observers that health care reform may lead to major Democratic losses in midterm elections.

Washington is "obsessed with the sport of politics," he said. "We have debated health care in Washington for more than a year. ... When's the right time? If not now, when? If not us, who?"

Meanwhile, the Senate's top Republican made it clear Sunday his party won't relax any of its efforts to halt the reform package.

"What the American people would like us to do is not make this gargantuan mistake," Senate Minority Leader Mitch McConnell, R-Kentucky, told ABC's "This Week."

If the bill does go through, avoiding a GOP filibuster by using the reconciliation tactic in the Senate, the battle moves to its next stage.

"Every election this fall will be a referendum on this bill," McConnell said.

Obama said Monday he's not inclined to take "advice about what's good for Democrats" from McConnell.

But "the issue here is not the politics of it," he asserted, saying Congress and the president were sent to Washington to "solve the big challenges."