Republican presidential candidate Jeb Bush speaks at a town hall meeting in Bedford, N.H., on Wednesday. (Brian Snyder/Reuters)

Jeb Bush and Donald Trump launched simultaneous strikes against Marco Rubio in this key early voting state Wednesday, signifying the growing threat Rubio’s rivals see in him as he climbs the polls in the Republican presidential primary.

Bush said in a television interview that Rubio followed his leadership in Florida and compared his lack of experience to President Obama’s — marking his sharpest attempt yet to draw a contrast with his longtime mentee.

Meanwhile, Trump continued ramping up his criticism of Rubio at a rally about 60 miles from the one Bush held here Wednesday evening, accusing Rubio of being soft on immigration and “very disloyal” to Bush.

The comments from Bush and Trump, which came amid Rubio’s rise in state and national surveys following the second televised debate, highlighted the senator from Florida’s new prominence in the race but also his status as a top target of criticism from his rivals.

“I’m a proven leader,” Bush told CNN’s Dana Bash before his town hall. “I disrupted the old order in Tallahassee. I relied on people like Marco Rubio and many others to follow my leadership, and we moved the needle.”

Republican presidential hopeful Donald Trump didn't mince words about his GOP rival Jeb Bush. Speaking at a town hall in New Hampshire, Trump criticized Bush's advertisements, saying, "What do you do when you're weak on immigration?" He also criticized Bush's relationship with fellow hopeful Sen. Marco Rubio. (C-SPAN)

Bush did not mention Rubio during his town hall. Afterward, he told reporters that he is “close friends” with Rubio but acknowledged that “it’s a little awkward” that the two are running against each other.

Still, Bush said Rubio “has every right to do it.”

Bush, a former Florida governor, mentored Rubio as he rose through the Sunshine State’s political ranks. Rubio went on to become state House speaker and won his Senate seat as a long-shot contender in 2010.

Rubio, 44, is running as a new generation candidate. Bush likened his pitch to Obama’s in 2008.

“Look, we had a president who came in and said the same kind of thing — new and improved, hope and change — and he didn’t have the leadership skills to fix things,” Bush said.

During his town hall, Bush criticized members of Congress for missing votes and reiterated his view that their pay should be docked for missing work. Data crunched by Vocativ from earlier this year showed Rubio was the most absent senator.

“Why is it that people miss votes in the United States Congress in such a rampant way?” Bush asked. He did not mention Rubio by name.

Speaking in Keene, Trump sought to drive a wedge between Bush and Rubio and criticized both of them.

“They hate each other. Trust me. I know,” he claimed.

Although Trump took a few shots at Bush on Wednesday night, he saved his most cutting insults for Rubio. Trump said Rubio gets only “12 people” to attend his events, is beholden to his major donors and is “very, very weak” on immigration.

A Rubio spokesman did not immediately respond to a request for comment on Bush’s remarks about him. On the campaign trail, Rubio has repeatedly declined to take direct shots at Bush. But on Monday, he urged voters not to “promote the next person in line or the most familiar name.”

Rubio has responded directly to criticism from Trump, calling him “touchy and insecure.”

There were clear contrasts in tone and setting between Trump’s event and Bush’s gathering. Trump referenced their dueling events in his remark as he went after the former governor.

“Jeb Bush is down the road — they’re expecting 125 people tonight,” Trump told his crowd, which he said the fire marshal capped at 3,564.

A Bush campaign aide estimated a crowd of 250 at Bush’s more intimate town hall.

“Nobody has crowds like us. Nobody. Including Bernie,” Trump added, referring to Sen. Bernie Sanders (Vt.), the Democratic White House hopeful who has been drawing massive turnouts.

Trump received huge cheers when he said Syrian refugees in the United States are “going back” if he wins. At Bush’s town hall, a Syrian American woman teared up as she asked Bush how he would address the refu­gee crisis, citing family members who left the country.

After Bush’s town hall, he sharply criticized Trump’s remark.

“Send them all back? To a hellhole?” Bush told reporters. “This is the same guy, by the way, that is also advocating exactly what seems to be supportive of Putin and his emergence in Syria. That’s not the proper policy for the United States.”

Retired neurosurgeon Ben Carson was also in New Hampshire on Wednesday, holding two town halls during the day and then meeting with local doctors in the evening.

Speaking at a retirement community in Exeter, Carson took only a few questions and told the crowd that he’s concerned with how politically correct the country has become, suggesting that a similar environment in Germany enabled Adolf Hitler to rise to power.

“If people don’t speak up for what they believe, then other people will change things without them having a voice,” Carson said. “Hitler changed things there, and nobody protested. Nobody provided any opposition to him.”

Speaking with reporters after the town hall, Carson said that he’s not comparing Hitler to Obama.

As he made his pitch here, Bush, sleeves rolled up, sought to pitch himself as a positive, experienced alternative to Trump.

“If you’re looking for the big guy on the stage talking in first-person singular . . . that’s not me,” he told the crowd.

Johnson reported from Keene, N.H.