Democratic presidential candidate Bernie Sanders speaks at a campaign rally Saturday in Rindge, N.H. (Photos by Charles Ommanney/The Washington Post)

PORTSMOUTH, N.H. — Appearing at a boisterous rally here, Democratic presidential candidate Bernie Sanders on Saturday repeatedly pushed back against claims that his agenda is too ambitious and that he lacks the chops to be commander in chief.

With just two days remaining before the New Hampshire primary, and with polls showing Sanders with a double-digit lead, he has faced a barrage of criticism from former secretary of state Hillary Clinton and her allies focused on whether his ideas are rooted in reality.

Speaking to an enthusiastic audience of more than 1,200 people, the senator from Vermont, a self-described democratic socialist, dismissed the notion that any of his proposals — including free tuition at public colleges and universal health care — are too “radical” to be implemented.

Sanders argued that “the world has changed” and students now need a college degree, not just a high school education, to obtain most jobs in the current economy.

“It is not a radical idea to say that public education should go through college,” he said of his plan, which would be funded by a new tax on Wall Street trades.

Turning to his plan to move to a single-payer, “Medicare for all” health-care system, Sanders was equally dismissive of concerns that Clinton has raised about a new congressional battle that would be necessary to replace the Affordable Care Act championed by President Obama.

“For the benefit of my critics, let me say it as loudly and clearly as I can: Health care is a right, not a privilege,” Sanders said, noting that 29 million Americans remain without health insurance.

Sanders said that while his critics say his vision is “nice,” they have reservations about whether they could overcome opposition by the private insurance companies and drug companies to get legislation through Congress.

“I say that when we stand together, we can,” Sanders said, drawing hearty applause from his crowd, which ranged in age from children with their parents to seniors.

Although he acknowledged some of his proposals are very costly, Sanders said they are justified to help the middle class because most new wealth created in the country in recent years has flowed to the upper class.

“We can afford these programs because we’re going to transfer some of that wealth back,” Sanders said.

On a day during which Clinton allies in New Hampshire held a conference call to question whether he’s ready to be commander in chief, Sanders continued to point to his 2002 vote against the Iraq War as indicative of his judgment on international affairs.

“Lately I have been lectured on foreign policy,” Sanders said. “The most important foreign policy issue in the modern history of this country was the war in Iraq. I was right on that issue. Hillary Clinton was wrong.”

Clinton, who was a U.S. senator representing New York at the time, voted to authorize force, a position she has since said was a mistake. Sanders was a member of the House when he cast his vote.

Clinton has accused Sanders of repeatedly pointing to that vote rather than talking about his plans going forward, including how he would deal with the Islamic State group.