Former U.S. Attorney General Eric Holder, who said he is considering a run for president, endorsed the Green New Deal's goal to make the United States a net zero carbon emitter in 10 years.

"This is our generation’s moonshot," he told reporters in Des Moines. "President Kennedy said we dared to go to the moon and do the hard things not because they’re easy but because they’re hard. This will be hard. This will cause dislocation, but the fate of the planet is at stake."

The Green New Deal resolution is a plan to combat climate change that calls for, among other things, meeting "100 percent of the power demand in the United States through clean, renewable, and zero-emission energy sources."

Holder said he's not as familiar with some of the deal's other provisions, but he supports the goal of net zero emissions. Several declared Democratic presidential candidates have also voiced their support.

Holder, who served as attorney general for six years under President Barack Obama, said he will decide in the next three to four weeks whether to run for president. If he does run, he said he would want to tackle climate change, economic inequality and "the protection of our democracy" by expanding voting rights.

"I’m concerned about the direction of the country," Holder said. "I think I’ve got some ideas and visions that I think would be useful to the nation."

Holder's visit to Iowa — his first as a possible presidential candidate — included a lecture to law students at Drake University's Law School and a talk with former Iowa Supreme Court Chief Justice Marsha Ternus sponsored by the Harkin Institute for Public Policy & Citizen Engagement.

In response to a question from an audience member about federal marijuana law, Holder suggested it might be time to legalize the drug and that he would vote to do so if he were a member of Congress.

"It seems to me that we’re at a point where we should think seriously about legalization," Holder said.

While attorney general in the Obama administration, Holder was part of the decision not to prosecute states that legalized marijuana for recreational use. He said he believed the states that legalized marijuana had effective regulations in place and should be allowed to experiment with legalizing it.

"We did some pretty gutsy and compelling things in not going after Washington and Colorado and allowing them to proceed with the recreational sale of marijuana," he told reporters.

Holder said he gets asked why he didn't decriminalize the drug, but said that's something Congress has to do. He said his voice didn't win out within the Obama administration, in terms of advocating for marijuana to no longer be classified as a Schedule I drug.

With regard to Medicare for All, which is supported by several Democratic candidates for president, Holder said the tactics come second to supporting the goal of universal health coverage. He rejected the idea of eliminating private insurance, as Sen. Kamala Harris, D-California, has suggested.

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"I would not want to take out of the system the notion of voluntariness and the notion of private plans if that’s what people want to do, but I’d really want to focus on that whole question of that goal of universal health care," he said.

Holder's Drake Law School and Harkin Institute talks focused primarily on voting rights. He is the chair of the National Democratic Redistricting Committee, a group that supports Democratic candidates and opposes gerrymandered legislative and congressional districts, and he said the issue would be central to his candidacy if he chooses to run for president.

"To me, this is the defining civil rights issue of our time because it strikes at the heart of who we are, as a country," he said. "The ability of all eligible citizens to have an equal voice in our democracy is not a privilege. It is a right."

Holder said Iowa's nonpartisan redistricting system is "one of the states that gets it right," adding "I'll be here the next day" if anyone tries to change it.

He criticized Iowa Republicans' proposal to change how judges are selected in Iowa to give lawmakers and the governor more control.

"That is simply the wrong way to go," he said. "The last thing you want to do is to have the people think that the judiciary is politicized."