Bernie Sanders predicts 'rough' campaign ahead but thinks Harris has 'very good chance to win'

Two-time presidential candidate Sen. Bernie Sanders predicted the campaign ahead will be "rough" but said he believes Vice President Kamala Harris "has a very good chance to win" the presidential election.

"She's certainly going to win the popular vote by millions of votes, and I think she has a great chance to win many of the battleground states," Sanders told "This Week" co-anchor Jon Karl on Sunday. "I think people are growing tired and fatigued with Trump's consistent and outrageous lies and I think no matter what people may think of Kamala Harris, I think they want stability in the White House."

The interview came just days after Democrats wrapped a lively convention where the party highlighted "freedom" as their overarching message for the campaign.

Asked about comments Harris made in her acceptance speech about ensuring the nation's military strength, Sanders cautioned against increased spending.

"The United States is now spending more than the next 10 nations combined on defense," he said. "I agree with the vice president. We want the strongest defense in the world, but I do think enough is enough. You're seeing military contractors profits soaring, and I think we can have the strongest defense in the world without spending a trillion dollars a year."

Sanders said Harris should focus her messaging on the economy and welfare of voters.

"We have more income and wealth inequality than we have ever had in the history of this country," he said. "So I happen to believe it's important that we end the embarrassment of having the highest rate of childhood poverty of almost any major country on earth."

Karl also asked Sanders if not giving the "Uncommitted" movement a platform at the convention was a mistake for Harris. Pro-Palestinian protesters and activists with the Uncommitted movement had repeatedly requested a speaking slot during the Democratic National Convention. The request, however, was denied by party officials.

Sanders has been one of the leading voices on Capitol Hill calling for a change in U.S. policy toward Israel as its war against Hamas in Gaza approaches its 11th month. He also has been outspoken against Israeli Prime Minister Benjamin Netanyahu.

"I happen to think that we should not be giving another nickel to Netanyahu’s right-wing extremist government," he said. "They certainly had a right to defend themselves against the atrocious Hamas attack. They never had the right, do not have the right to go to war against the entire Palestinian people, kill 40,000, injure 80,000 and destroy the health care system, the educational system and the civilian infrastructure."

He added, "American taxpayer dollars should not go to starve children in Gaza."

Karl then asked Sanders about the nation's immigration struggles and how Harris' views on the southern border have shifted.

"When Harris ran for the Democratic nomination against you and others in 2020, she said she favored decriminalizing illegal border crossings. She even suggested she was she would be in favor of abolishing [Immigration and Customs Enforcement]," Karl said.

"We have a crisis at the border. We’ve got to make sure that fentanyl does not get into this country. We have to crack down on illegal immigration," Sanders replied. "But we need comprehensive immigration reform. And I suspect that's what the vice president supports."

Republicans have attacked Harris by tying her to the high level of migrant encounters and apprehensions at the U.S.-Mexico border over President Joe Biden's term. Harris has tried to counter that by highlighting her time as a prosecutor and support for the failed bipartisan border policy reform bill. Harris previously supported decriminalizing illegal border crossings and said she believed U.S. Immigration and Customs Enforcement's "mission ... is very much in question and has to be reexamined."

ABC News' Fritz Farrow, Will McDuffie and Gabriella Abdul-Hakim contributed to this report.