LOS ANGELES - Thousands of residents in Southern California Wednesday urged US Congresswoman Judy Chu to vote against any cuts to social security, medicare, or medicaid benefits.

A group of residents, calling themselves "citizen co-signers" of a letter authored by Congressmen Alan Grayson and Mark Takano handed 1,029 signatures over to her.

"We will vote against any and every cut to medicare, medicaid, or social security benefits -- including raising the retirement age or cutting the cost of living adjustments that our constituents earned and need," read the letter addressing US President Barack Obama.

"If Republicans ... insist on benefits cuts, that proves they are not concerned about the deficit, but instead are trying to tear the social safety net and cause pain for our constituents who can least absorb it," it said.

"We must do whatever it takes to protect these vital benefits from cuts," it said, adding "we firmly believe that the best way to reduce our deficit and make our economy grow is to create jobs."

Nationwide, over 200,000 people, as well as national progressive organizations, have signed on the letter, said Matt Wall, spokesman for the national progressive organizations.

Benefit receivers became worried as Obama, who had promised no cuts, offered cuts to popular social programs as a bargaining chip in the ongoing sequester debate.

Obama "reached out" to lawmakers from both parties last Saturday floating a proposition to cut spending in order to appease Republican demands and the "deficit scolds," according to White House senior economic official Gene Sperling.

A study by the Center for Economic and Policy Research showed that the proposed change to social security benefits would cost an average 65-year-old retiree about $650 a year by age 75.

Another study by the Kaiser Family Foundation said raising the medicare age would lead to higher insurance premiums, not just for 65- and 66-year-olds but also for employers and younger patients.

Republicans have proposed to gradually raise the eligibility age to 67 for those now aged under 55, so that current retirees and those nearing retirement would not be affected. The social security eligibility age for full benefits has been rising gradually to 67.

It is reported that any American reaching retirement age in the next 20 years would take more than three times as much out of medicare as he or she contributed in taxes. By 2030, the United States will have twice as many retirees as in 1995.