GLENSIDE, Penn. (AP) — President Barack Obama accused insurance companies of placing profits over people and said Republicans ignored long-festering problems as he sought to build public support for his stalled health care legislation.

Obama's pitch on Monday in this Philadelphia suburb — along with a planned stop in St. Louis on Wednesday — comes as the president begins an all-out effort to get Congress to pass his health care proposals.

The next two weeks will prove decisive, with the White House pushing for a vote in the House of Representatives by March 18, when Obama leaves for an Asia trip.

"Let's seize reform, the need is great," Obama said at an appearance here that had the feel of a campaign rally.

The United States is the only developed nation that does not have a comprehensive national health care plan for all its citizens. About 50 million of America's 300 million people are without health insurance. Most of those who are insured rely on their employers for coverage.

The president said dismissively that Republican critics in Congress contend they want to do something about rising health care costs but failed when they held power. "You had 10 years. What happened? What were you doing?" he said to applause from an audience at Arcadia University.

Obama made his appeal as Democratic leaders in Congress worked on a rescue plan for sweeping changes in health care that seemed earlier in the year to be on the brink of passage. The current two-step approach calls for the House to approve a Senate-passed bill despite opposition to several of its provisions, and for both houses to follow immediately with a companion measure that makes a series of changes.

Republicans dismissed Obama's argument instantly.

"The American people have heard all this rhetoric from the president before, and they continue to say loudly and clearly they do not want a massive government takeover of health care," said House Republican Leader John Boehner of Ohio, who added the president's plan was "heavy on snake oil."

Democratic Sen. Arlen Specter, who traveled with Obama to the event in suburban Philadelphia, said the president's determined tone was "as fiery as I've seen him since the campaign."

Obama has long identified the insurance industry as an obstacle to changes along the lines he seeks, but the administration's actions and rhetoric seem to have escalated in recent days.

The president's proposal would give the government the right to limit excessive premiums increases — a provision included after one firm announced a 39 percent increase in the price of individual policies sold in California.

Insurers have blamed rising rates on the growing prices of prescription drugs, hospital stays and other medical items.

The president's remarks came nearly a week after he took command of a final bid to pass his health care legislation and told a White House audience he wanted Congress to vote yes or no within a few weeks.

In the days since, he has met with two groups of wavering Democratic lawmakers, stressed the health care issue in his weekly radio and Internet address, and announced a trip to St. Louis for later in the week.

Full Democratic support is far from certain. Some party moderates are uneasy about the cost of the $1 trillion bill and its language on abortion, and some House Democrats are suspicious of whether their Senate colleagues would follow through on promises to work out the differences in the bills.