When candidates are on the trail, they recycle stump speeches or favorite lines. Republican presidential candidate Donald Trump has a few favorite attack lines:

Marco Rubio’s sweat

The room was hot during the second Republican presidential debate in September -- and it showed on the candidates’ faces.
Following the debate, Trump attacked his fellow GOP candidates for sweating on stage, zeroing in on Sen. Marco Rubio, and since then the attacks on Rubio’s perspiration become more common. According to Politico’s count, at least eight times in the last seven weeks, Trump has brought up Rubio’s sweat.
“Rubio, I've never seen a young guy sweat that much. He's drinking water, water, water,” Trump said at a speech to the South Carolina African Americans Chamber of Commerce. “I never saw anything like this with him, with the water.”
Trump went as far as to send the Florida senator a “care package” including 24 bottles of water and a note, “Since you’re always sweating, we thought you could use some water. Enjoy!”
On the day Rubio announced he was running for president, Trump Tweeted that Rubio was “sweating profusely!”
“I drink water. So what? And I only sweat when it’s hot,” Rubio responded, Fox News reported.

Jeb Bush’s “low energy”

Jeb Bush released a video in September attacking Trump’s record, claiming Trump was more Democrat than Republican.
On ABC’s "Good Morning America," Trump explained Bush’s attacks: “He’s a very low energy kind of guy and he had to do something.”
Trump also retaliated with a video posted to his Instagram asking, “Need some low energy?...Jeb for all your sleeping needs.”
Multiple times, Trump has called Bush a “low-energy person” including on ABC News’ “This Week,” on MSNBC, during a New Hampshire townhall.
“More energy tonight. I like that,” Trump said when he and Bush got into an argument during the second GOP debate about donors and special interest.
At another moment during the September debate, Bush said his Secret Service code name would be “Ever Ready.” He turned to Trump, “Very high energy, Donald.” Trump then gave Bush a low-five.
Lately, Trump has been recycling the “low-energy” attack to go after Ben Carson.

Comparing Hillary Clinton to Gen. Petraeus

Retired General David Petraeus resigned as CIA Director in 2012, admitted to leaking classified information to his mistress, and was ultimately put on probation and fined $100,000.
Trump in past months has compared Democratic presidential candidate Hillary Clinton to Petraeus, calling her use of a private server General Petraeus “on steroids.”
"What she did is far worse than what General Petraeus did and he's gone down in disgrace," Trump told CNN. "What he did is not as bad as what Hillary Clinton did.”
Trump told ABC’s Jonathan Karl in September that Clinton was in “deep trouble” with her emails: “How they did that to General Petraeus and they leave her alone is beyond anyone’s comprehension.”

Calling candidates ‘puppets’ to donors

Trump is funding his own campaign and bashing candidates for resorting to donors.
“I’m putting up 100 percent of my own money,” Trump declared during the most recent GOP debate this past month.
Other candidates are “puppets,” according to Trump.
“Jeb Bush is a puppet to his donors,” Trump said at the Iowa State Fair.
Last month, Trump tweeted that casino mogul “Sheldon Adelson is looking to give big dollars to Rubio because he feels he can mold him into his perfect little puppet.”
During an interview on “Meet the Press,” Trump called Clinton a “puppet” to campaign donors.

Candidates’ polling numbers

When Trump is up in the polls, he wants everyone to know it. And when other candidates are down in the polls, and attacking Trump, Trump wants everyone to know that as well.
Rand Paul hasn’t been doing well in the national polls and Trump believes Paul’s bad polling numbers will lead the Kentucky senator to drop out.
Louisiana Gov. Bobby Jindal who had been attacking Trump for a while also has not been polling nationally more than single digits. Trump took notice.
“Well, look, Jeb has had a very hard time. He’s way down in the polls. He’s doing very poorly,” Trump told ABC’s George Stephanopoulos. “He’s embarrassed by what’s happening. So he has to attack me to try to get his numbers up,”
In an interview with Bloomberg that aired yesterday, Trump argued that Rubio is “nowhere in the polls, I don’t think he’s personally going to make it.”
Trump couldn’t explain Ben Carson’s surge in the polls, who is leading Trump in a few polls.
“I don't get it, to be honest with you,” Trump said on MSNBC.
During CNBC’s Republican debate, Trump took aim at Ohio Governor John Kasich.
“I’m never going to attack but then his poll numbers tanked,” Trump said of Kasich.

ABC News