WASHINGTON (AP) — In a victory for President Obama, the Democratic-controlled House narrowly passed landmark health care legislation Saturday night to expand coverage to tens of millions who lack it and place tough new restrictions on the insurance industry. Republican opposition was nearly unanimous.

The 220-215 vote cleared the way for the Senate to begin debate on the issue that has come to overshadow all others in Congress.

A triumphant Speaker Nancy Pelosi likened the legislation to the passage of Social Security in 1935 and Medicare 30 years later.

‘‘It provides coverage for 96 percent of Americans. It offers everyone, regardless of health or income, the peace of mind that comes from knowing they will have access to affordable health care when they need it,’’ said Rep. John Dingell, the 83-year-old Michigan lawmaker who has introduced national health insurance in every Congress since succeeding his father in 1955.

In the run-up to a final vote, conservatives from the two political parties joined forces to impose tough new restrictions on abortion coverage in insurance policies to be sold to many individuals and small groups. They prevailed on a roll call of 240-194.

Ironically, that only solidified support for the legislation, clearing the way for conservative Democrats to vote for it.

The legislation would require most Americans to carry insurance and provide federal subsidies to those who otherwise could not afford it. Large companies would have to offer coverage to their employees. Both consumers and companies would be slapped with penalties if they defied the government’s mandates.

Insurance industry practices such as denying coverage on the basis of pre-existing medical conditions would be banned, and insurers would no longer be able to charge higher premiums on the basis of gender or medical history.

In a further slap, the industry would lose its exemption from federal antitrust restrictions on price gouging, bid rigging and market allocation.