As the Republican Party continues to be quite explicit about its ultimate goal of slashing the safety net to pay for deficit-exploding tax cuts for their wealthy donors, Sen. Bernie Sanders (I-Vt.) joined 150 Democrats from both houses of Congress on Thursday to launch the Expand Social Security Caucus, which will work to combat the GOP's efforts to gut the program and move to make it even stronger.

"We are here today to say very loudly and very clearly that at a time when millions of seniors are trying to survive on $12,000 or $13,000 a year, our job is not to cut Social Security," Sanders said in a statement. "Our job is to expand Social Security so that everyone in America can retire with dignity and respect."

In a jab at the soon-to-be-retired Wisconsin congressman whose lifelong dream has been to obliterate the safety net, Sanders added on Twitter, "Hear that, Paul Ryan?"

The formation of the Expand Social Security Caucus is another strong indicator of how successful progressive activists and lawmakers like Sanders have been in changing the Democratic Party's position on the crucial program, which former President Barack Obama offered to cut on multiple occasions as part of a "grand bargain" with the Republican Party.

In a statement on Thursday, Sen. Elizabeth Warren (D-Mass.) declared that the new caucus "won't allow Social Security be cut by one cent—and instead we will fight to expand it."

"Social Security is a lifeline for seniors and Americans with disabilities," Warren added. "The rich and powerful have rigged our economy to make themselves richer, while working families face a massive retirement crisis. If this government really works for the people, it should protect and expand Social Security."

A full list of the founding members of the Expand Social Security Caucus can be viewed here.

Watch the press conference officially launching the caucus: