President Obama argued Wednesday night that Donald Trump has yet to answer how he'll make America "great again," and indicated he doubts Trump will be able live up to his own campaign slogan.

Obama was in Elkhart, Ind., where he answered a question about what do about lost manufacturing jobs, and said Trump doesn't have a "magic wand" to bring the jobs back.

"Well, how exactly are you going to do that?" Obama rhetorically asked Trump, without naming him. "There's no answer to it. He just says 'well, I'm going to negotiate a better [trade] deal.' Well, how exactly are you going to negotiate that? What magic wand do you have? And usually the answer is, he doesn't have an answer."

Obama also pushed back on the premise of Trump's campaign, which is that America needs to be made great again.

"The notion that America is some how in decline is not born out in the facts," Obama said during a PBS-sponsored town hall.

Asked why he doesn't mention Trump by name, Obama quipped: "He seems to do a good job mentioning his own name … I'll let him down his advertising for" himself.

Obama breezed past a question about whether he considers Trump's popularity a personal rebuke, saying Trump is simply a "more colorful character" delivering the same anti-Obama, anti-Democrats message that Republicans have hammered for decades.

Since late April, Obama has worked to alter the Republican narrative about the economy under his stewardship. In that vein, Obama returned to Elkhart, the first city he visited as president, to tout his economic record.

"The story of Elkhart's recovery is the story of America's recovery," Obama wrote in announcing his plan to visit the nation's recreational vehicle manufacturing capital. "America is the strongest country on Earth; it's economy is the most durable on Earth," he told the 200-odd people gathered in in a historic local theater to hear him Wednesday.

But he faces some pressure on an issue the GOP has raised for years now: federal regulations. A family farmer used the town hall to ask Obama about regulations that have hurt companies.

"I don't doubt that some elements of the regulations I put in place have probably put a burden on you," Obama admitted. "I'm not interested in regulating just for the sake of regulating," Obama added, saying some costly regulations are necessary.

"[T]here are some things, like making sure we've got clean air and clean water, making sure that folks have health insurance, making sure that worker safety is a priority. That, I do think, is part of our overall obligation ... as an advanced nation to make sure that we're doing the right thing."