The Senate abandoned an effort to expand federal coverage for Medicaid abortions in the face of strong opposition from the House and the White House.

The Senate in July had voted 73-19 to allow federal financing for Medicaid abortions for women who are victims of rape or incest, but it backed down on Tuesday in a bow to political reality.Under current law, federal spending for Medicaid abortions is permitted only if the procedure is needed to save a woman's life. The House reaffirmed its support for that policy last week, and in the process rejected the Senate's proposal for rape and incest exceptions.

President Reagan had promised to veto a $140 billion spending bill containing all the fiscal 1989 money for the departments of Labor, Health and Human Services, and Education if it came to him with the Senate's abortion provision.

The Senate on Tuesday voted 47-43 to kill a motion insisting on the expanded Medicaid abortion coverage it had approved earlier.

"It's stand up and be counted time," said Sen. Lowell Weicker, R-Conn., the chief proponent of expanded Medicaid coverage.

"We're going to see how politically expedient we want to be," added Sen. James Exon, D-Neb., sponsor of the provision adopted by the Senate in July.

Sen. Lawton Chiles, D-Fla., chairman of the subcommittee that handled the spending bill, told his colleagues it would be futile to resist the will of the House and White House.

"We're talking about a House that we're 50 votes short in. We're talking about a president that's going to veto the bill. We're talking about a clock that's ticking," Chiles said.

Countered Exon: "Sometimes I think we quiver and retreat all too soon."

It took Chiles two tries to kill Weicker's motion insisting on the Senate abortion position. He lost the first vote 46-44 but prevailed on the second, 47-43.

The outcome was hailed by the National Right-To-Life Committee as "a sharp setback for the pro-abortion movement" and those groups, who label themselves pro-choice, had to agree.

Kate Michelman, executive director of the National Abortion Rights Action League, said "politics played a heavy role" in the vote.

"Arms got twisted so that our friends voted against us," she said.

"We are terribly disappointed," said David Andrews, executive director of the Planned Parenthood Federation of America. "These are clearly cases that cry out for public funding."