The super PAC backed by House Republican leadership is opening six new field offices in seats the GOP is trying to hold this fall. 

Congressional Leadership Fund is adding offices in Illinois, Kansas, North Carolina and Texas, bringing its total number of offices around the country to 40. 

CLF is known for spending money on TV advertising and has often been the largest outside spender in contested special elections since President Donald Trump was elected. The group spent more than $3.3 million alone in the recent special election in Ohio’s 12th District. But CLF has also put a large emphasis on field efforts, making more than 18 million voter contacts since February 2017. 

The new offices in Illinois are in the 13th District, represented by three-term Rep. Rodney Davis, and the 14th District, where Rep. Randy Hultgren has served since 2011. Inside Elections with Nathan L. Gonzales rates those races Likely Republican and Solid Republican, respectively.

In North Carolina, CLF is adding offices in the 2nd District, where Rep. George Holding’s race is rated Solid Republican, and in the 9th District, where former pastor Mark Harris recently defeated incumbent Robert Pittenger for the GOP nomination. That race is rated Tilts Republican. 

CLF is opening an office in Kansas’ open 2nd District. After the contenders for that race were set in a primary earlier this week, CLF wasted no time going on the air with a TV ad tying the Democratic nominee to House Minority Leader Nancy Pelosi. Inside Elections rates the race Leans Republican. 

CLF is also opening an office in Texas’ 32nd District, where former National Republican Congressional Committee Chairman Pete Sessions is running in a Toss-up race. 

Watch: What We Learned From the Last Special Election Before November