CNN  — 

Entering the stretch run of the 2018 midterm elections, the ad wars are escalating. One major Republican group is playing defense, pouring money into GOP-held seats in races CNN has considered Likely or Lean Republican in Key Race Ratings.

The Congressional Leadership Fund – the leading GOP super PAC, affiliated with House Republican leadership – announced on Thursday that it was adding $13 million to its fall TV ad reservations, bringing the group’s total TV spending to $85 million. The additional $13 million includes targeting five new congressional districts: IL-13, MI-06, NC-02, NM-02 and NV-03.

Michigan congressman Fred Upton, former chair of the Energy and Commerce committee, is among those CLF will now spend on this fall.

The races in Illinois, Michigan and North Carolina feature Republican incumbents and are listed as Likely Republican in CNN’s Key Race ratings. The race in New Mexico is for an open seat rated Lean Republican and the race in Nevada is for an open seat rated Lean Democratic.

The Congressional Leadership Fund has spent the opening weeks of the fall campaign season launching a torrent of attack ads.

The group has released over 45 new spots in September alone, nearly all of them attacking Democrats. The ads criticize Democrats for opposing Republican policies – like the tax cuts passed last year – while hammering Democratic candidates as out of touch and beholden to House Minority Leader Nancy Pelosi of California, a favorite conservative target.

Congressional Leadership Fund Executive Director Corry Bliss told CNN about the importance of defining candidates early in the race.

“CLF has been saying for over a year that this is a very challenging environment, and things have to be done differently,” Bliss said. “In order to win in November, you need to win in September. Beginning in August, CLF was aggressive, going in early to key races across the country, attacking and defining Democratic candidates.”

“In this environment, if you are down 5 you’ll lose. If you’re up 5, you probably win,” Bliss said.

According to data obtained via Kantar Media/CMAG, the Congressional Leadership Fund has been the second biggest spender on TV advertisements in 2018 through this week, coming in after One Nation, a conservative nonprofit affiliated with the Senate Leadership Fund, the Mitch McConnell super PAC. The Congressional Leadership Fund has aired $25.65 million worth of TV ads so far.

And the super PAC has money to spend. It had more than $61 million in cash on hand at the end of August, powered in part by the $30 million contribution the group received from Sheldon and Miriam Adelson – kingmakers in GOP politics – in May. The group also received $10 million in May from Timothy Mellon, the son of Paul Mellon and current chairman of Pan Am Systems, a New Hampshire-based transportation company.

Democrats need to pick up 23 seats to capture the House majority, and CNN currently rates 30 House races as pure toss-ups, among dozens of other competitive races. That’s put Republicans on defense. Here’s a look at the districts where the Congressional Leadership Fund has spent the most on TV advertising so far.

Among the top targets: a pair of Kansas House races in the 2nd and 3rd districts, where retirements and shifting political dynamics have created openings for Democrats in a traditionally red state. A trio of California House races in CA-39, 45 and 48 are also top Democratic pickup targets. And two races in Colorado and Kentucky feature prized Democratic recruits with compelling biographies that include military service.

Many of the Congressional Leadership Fund’s attack ads follow a similar script, portraying the wave of Democratic candidates – many of them running for office for the first time – as excessively liberal, unethical and out of touch.

One such ad – targeting Democrat Scott Wallace in PA-01 in his race against Rep. Brian Fitzpatrick – is a classic of the attack ad genre, while also touching on tax policy. A narrator reads, “(Scott Wallace) inherited a hundred million bucks. But Wallace repeatedly failed to pay his own taxes. Wallace was hit with a $70,000 lien for unpaid taxes. But now, Wallace wants to go to Congress to raise our taxes. Delinquent taxes for him, higher taxes for us. That’s really, really rich.”

The Wallace campaign told PoliticsPA in response to the ad, “Brian Fitzpatrick and his allies are taking one clerical mistake and distorting it. … Scott Wallace has paid all his taxes in full, period. The incident was a clerical mix-up. When he found out he owed more in taxes, he paid them in full.”

Taxes and tax policy have in fact been the top issue in Congressional Leadership Fund ads so far this cycle, with over $5.4 million worth of tax ads aired by the group so far. More than $2 million of those tax ads have focused specifically on reform.

One ad in a top target district, Kansas’ 2nd, hammers the Democrat, Paul Davis, for opposing the GOP tax cuts. “Davis is so liberal, he opposed middle-class tax cuts that are saving Kansas families over $2,000 a year. He calls that a ‘bad deal.’ We can’t afford Paul Davis in Congress,” says the narrator.

Asked about the Congressional Leadership Fund’s messaging strategy, Bliss said, “Most important: Attack and define first-time candidates as being unethical and out of touch. The outside group must always be the hammer first and foremost.”

“If CLF is running attack ads in a race, it provides an opportunity for the campaign to run positive ads,and focus on their achievements,” he explained. “The added benefit of CLF raising so much money and being aggressive early: It provides cover to members and allows them to run positive ads and educate their constituents about what they’ve achieved and why they should be re-elected.”

Bliss pointed to three races in particular – KY-06, OH-01 and CA-39 – where the Congressional Leadership Fund spent early and aggressively and, he says, halted or reversed worrisome trends for Republicans.