04/05/2013 06:24 pm ET

Bernie Sanders Will Do 'Everything In His Power' To Block Obama Budget's Social Security Cuts

Sen. Bernie Sanders (I-Vt.) on Friday aggressively pushed back on President Barack Obama's budget proposal, calling it a "bitter disappointment" and promising that the entitlement cuts contained in the plan wouldn't pass under his watch.

“I am terribly disappointed and will do everything in my power to block President Obama’s proposal to cut benefits for Social Security recipients through a chained consumer price index," Sanders said in a statement, blasting the plan to change how cost-of-living adjustments for Social Security payments are calculated.

As HuffPost explained on Friday, the proposal is highly unpopular among senior citizens:

Obama has proposed reducing future benefits by making annual cost-of-living adjustments less generous. Almost every year, the Social Security Administration adjusts benefits based on the prices of various consumer goods, including things like food and health care. Obama's proposal would change the way the government measures inflation from the current Consumer Price Index to what economists call "chained CPI."

Last year, beneficiaries received a 1.7 percent boost. If the adjustment had been calculated using chained CPI, seniors and other Social Security recipients would've received a 1.4 percent adjustment. The policy switch would save more than $100 billion over 10 years.

Sanders insisted Friday that the budget would "hurt a lot of people,” and noted earlier this week that it marked a reversal from Obama's 2008 position.

“In 2008, candidate Barack Obama told the American people that he would not cut Social Security," he said. "Having him go back on his word will only add to the rampant political cynicism that our country is experiencing today.”

As HuffPost reported on Friday, Sanders isn't the only one outraged at Obama over the proposal. Progressive-leaning groups quickly responded to the news by promising to mount primary challenges against congressional Democrats who sign on to the plan.