NEWARK, N.J. (CBSNewYork/AP) — Barack Obama hit the campaign trail for the first time as an ex-president Thursday, stumping for Democratic gubernatorial candidate Phil Murphy in Newark.

As WCBS 880’s Alex Silverman reported, Obama never mentioned President Donald Trump by name on Thursday. But it was hard not to hear certain lines as digs at his successor.

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“It’s not just enough to be a successful businessman,” Obama said. “What’s important is, what kind of citizen are you?”

Other times, Obama was more direct.

“Some of the politics we see now we thought we put that to bed,” Obama said. “That’s folks looking 50 years back. It’s the 21st century, not the 19th century.”

He said nothing frustrates him more than people who don’t vote, but do complain.

“And you can’t take this election or any election for granted,” Obama said. “I don’t know if you all notice that.”

Murphy, Obama’s former ambassador to Germany, is facing Republican Lt. Gov. Kim Guadagno. They held their last debate on Wednesday night.

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Guadagno’s spokesman, Ricky Diaz, suggested it’s Murphy and not Republicans who are divisive.

“Phil Murphy is the one who will divide New Jersey by raising taxes so high that only the über rich like him will be able to afford to live here,” he said.

Obama also spoke Thursday at a rally for Democratic Virginia gubernatorial candidate Ralph Northam, who is now lieutenant governor.

“Why are we deliberately trying to misunderstand each other, and be cruel to each other and put each other down? That’s not who we are,” Obama said at the Virginia rally in front of several thousand supporters.

The first black president offered himself as proof that the country could move forward, telling the crowd in Richmond, the former Capitol of the Confederacy, that he is a distant relative to Confederate President Jefferson Davis on his mother’s side.

“Think about that,” Obama said. “I’ll bet he’s spinning in his grave.”

Obama’s remarks came on the same day Former President George W. Bush denounced bigotry in Trump-era American politics, warning that the rise of “nativism,” isolationism and conspiracy theories have clouded the nation’s true identity.

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)