The most expensive Senate races
With more than $200 million outside spending pouring in, the North Carolina Senate race has been the most expensive congressional race so far in 2020, followed by the Iowa and South Carolina Senate races, according to the Center for Responsive Politics’ analysis of campaign spending records.
In all of the 10 most expensive Senate races this year, Democrats have been vastly outraising and outspending Republicans, especially where Democratic challengers are competing against Republican incumbents. Meanwhile, big-money outside political groups from across the aisle have been driving up the spending.
Across the Senate battleground, North Carolina is a state that perhaps more than any other could ultimately tilt control of the chamber - reflected in a stunning $280 million in campaign money and outside money being poured into the state.
In the competitive race, recent polling shows Republican Sen. Thom Tillis trailing slightly behind Democrat Cal Cunningham. The candidates have spent more than $64 million in the contest, with Cunningham raising and spending more than twice the amount from Tillis, while outside groups across the board have spent upwards of $215 million supporting the two.
Similarly, the contest between Republican Sen. Joni Ernst and Democratic challenger Theresa Greenfield in Iowa has attracted far more spending from political interest groups than the candidates. The candidates’ campaigns have spent about $64 million so far, but outside groups have funneled at least $170 million into the race, with more than $94 million going into unseating the incumbent senator and more than $74 million spent to fend off the challenger.
South Carolina rounds out the top three, with more than $209 million being spent in a state that is surprisingly competitive this cycle for the Senate. The candidates have spent far more than outside groups though, with $164 million being spent by Democrat Jaime Harrison and GOP Sen. Lindsey Graham, compared to $45 million by outside groups. Harrison’s campaign, in particular, raised a whopping $107 million and spent $104 million of that by mid-October, compared to Graham, who raised $72 million and spent $60 million.
Arizona and Maine finish in the top five, with more than $208 million and $180 million spent in each respective race. Similar to South Carolina, the Arizona candidates’ campaigns -- Sen. Martha McSally and Democrat Mark Kelly -- have poured more money into the contest -- more than $125 million -- compared to outside groups at roughly $83.4 million.
In Maine, where outside groups are spending more than candidate campaigns, Democratic challenger Sara Gideon has raised and spent twice the amount Republican Sen. Susan Collins, but about the same amount of outside money has supported the two candidates.
-ABC News' Kendall Karson and Soorin Kim