CNN  — 

Let the air wars begin.

Right to Rise, the super PAC supporting former Florida Gov. Jeb Bush’s presidential campaign, is laying down $24 million for an ad buy that begins Tuesday in Iowa and New Hampshire, according to a source familiar with buy.

The major purchase comes as the political arm of the outside group Club for Growth announced ads taking on Donald Trump’s record on fiscal issues. The ads could shift the dynamics in a race where Bush has been sliding as Trump has grown in strength.

RELATED: Club for Growth targets Donald Trump with $1 million in Iowa ads

“We’re moving beyond the earned media phase into more of an air wave where Bush’s money advantage can now begin to make a difference in the early state contests,” said Republican Strategist Kevin Madden.

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Madden added, “One of the challenges Bush has is that there is a narrative out there – that Bush is the moderate in the race and this ad is an attempt to fill in the blanks for voters on what was actually a conservative record in Florida.”

The spot, which will be up Tuesday in Iowa and New Hampshire and later in South Carolina, touts Bush’s record on issues like spending and taxes, as well as education where his record goes beyond just support for Common Core federal education standards, and where his reputation as a reformer is consistent with what a lot of grassroots conservatives want to see.

Of the $24 million, $6 million will be spent in Iowa, $12 million in New Hampshire and $4.7 million will be spent in South Carolina.

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It’s a record that Bush has been eagerly trying to contrast with what he describes as the questionable history of his biggest rival. Bush has made direct comparisons with Trump in his recent stump speeches, pointing out his own history of taking conservative positions while highlighting Trump’s past of supporting Democrats and their policies.

But notably absent from the ad are any digs against Trump; instead, it focuses entirely on a positive message about Bush. Yet earlier this month, Right to Rise released a web video arguing that Trump and Hillary Clinton are two sides of the same coin, raising questions over whether the committee would throw money behind the video and make it the group’s first major TV commercial.

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The whopping ad buy marks a little less than a quarter of the $103 million sum the committee raised in the first half of the year, giving Bush his biggest advantage over his Republican rivals: money.

It also represents a substantial uptick from the $10 million plus that Right to Rise initially announced that it would spend last month on the ad buy. The increase comes as Bush has steadily faded in the polls. The latest survey, released by CBS News and the New York Times this morning, shows Bush in third place with only 6% support among Republican voters.

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Meanwhile Trump and retired neurosurgeon Ben Carson – two candidates who’ve thrived on their outsider, anti-establishment status – take the top two spots in the poll, at 27% and 23%, respectively. Former Arkansas Gov. Mike Huckabee and Sen. Marco Rubio of Florida tie with Bush at 6%, while all other candidates come in at 5% or less.

The Bush super PAC buy comes as the Club for Growth stepped up Tuesday and launched a $1 million attack against Trump, accusing him of being “just another politician.”

Club for Growth President David McIntosh said that the group’s ads begin running Thursday in Iowa, but acknowledged that it would take more than $1 million to put a dent in Trump’s popularity.

RELATED: Club for Growth targets Donald Trump with $1 million in Iowa ads

CNN’s Tom LoBianco contributed to this report.