CNN

Palin campaigned in New Mexico Sunday.

ROSWELL, New Mexico (CNN) - Sarah Palin on Sunday levied some of her toughest attacks to date against Barack Obama, accusing him of experimenting with socialism and charging ACORN, the embattled community organizing group to which Obama has been linked, with attempting to undermine the sacrifices of United States troops abroad.

Palin has made indirect references to socialism in recent days while attacking Obama’s tax plan, usually in the context of Joe “the plumber” Wurzelbacher’s remark that Obama’s tax plan sounds “socialist.”

On Sunday, she went a step further.

“Barack Obama calls it spreading the wealth,” she said. “Joe Biden calls higher taxes patriotic. But Joe the plumber and Ed the dairy man, I believe that they think that it sounds more like socialism. Friends, now is no time to experiment with socialism.”

Her nod to “Ed the dairy man" was apparently a reference to a voter in the audience.

The vice presidential candidate claimed Obama's plan to issue tax credits to lower-income workers amounts to little more than a series of government handouts.

“He claims that he'll cut income taxes for 95 percent of Americans, but the problem is more than 40 percent of Americans pay no income taxes at all," she said. "So how can you cut income taxes for folks who don't pay them?”

Obama’s tax plan calls for tax relief for 95 percent of workers and their families. Though non-partisan tax policy organizations agree that 40 percent of Americans don’t pay income tax, many of those are lower-income earners who file payroll taxes through their employers.

"Since he can't reduce taxes on those who pay zero, he wants the government to send them a check that's called a tax credit," she said. "And where is he going to get the money for all those checks that he will cut? By raising taxes on America's hard-working families and our small businesses."

Tax credits are also the centerpiece of John McCain's health care plan.

Saying once again that "it's not negative campaigning" to question Obama's associations, Palin turned up the heat on the Democrat over his past ties to ACORN, and said the group - accused of fraudulently registering thousands of voters - is trying to steal a basic freedom that American military forces overseas are fighting to protect.

“We've sent our young men and women over to a war zone to protect our rights and our freedoms," she said. "A part of that is our right to free and fair elections. How dare anyone try to take that away from the good Americans who are fighting for us to ensure all of that?”