The southern New Mexico congressional district won by Democrat Xochitl Torres Small may prove to be the most-expensive race in state history.

Torres Small defeated Republican Yvette Herrell and will replace Republican Steve Pearce, who ran for governor instead of seeking another term.

As anyone who watched TV in the weeks ahead of the election, candidates and outside groups targeted the race in the national battle over the U.S. House of Representatives.

In all, candidates and outside groups spent $12.7 million on the race according to the Center for Responsive Politics, with several weeks of spending from candidates not due until Dec. 6. That report will include campaign finance data through Nov. 26.

The record is currently the $14.8 million spent in the 2006 1st Congressional District race.

The high-spending 2018 New Mexico race echoed a national theme. The cycle is the most expensive midterm on record thanks to “a truly staggering increase in outside spending,” according to OpenSecrets, a project of the Center for Responsive Politics. In all, $5.2 billion was spent on campaigns, including $1.31 billion by outside groups.

In this year’s 2nd Congressional District race, outside groups spent $7.7 million, shattering the previous record. Candidate spending, through Oct. 17, exceeded $4.9 million.

Outside spending this year easily surpassed the 2006 race for the 1st Congressional District, the state’s only congressional race to have previously attracted more than $5 million in spending from outside groups. In recent years, court decisions have narrowed campaign finance laws, allowing for more outside spending in congressional races.

Torres Small was one of many Democratic candidates nationwide who broke fundraising records, banking nearly $3.8 million through Oct 17. Of that, she spent $2.79 million through the same date. Herrell raised $1.22 million and spent $818,000 through the same time period. The two had a combined $1.4 million cash-on-hand as of the 17th, and likely spent that money down in the final weeks of campaigning.

For now, the razor-thin 2006 1st Congressional District race still holds the crown for most-expensive overall, at least until the next campaign finance reports come in.

Republican incumbent Heather Wilson faced Democratic Attorney General Patricia Madrid in more than a decade ago, another time when Democrats successfully took the House of Representatives.

Previous record holder

In 2006, Heather Wilson was seeking her fifth full term in Congress. She first won the Albuquerque-area congressional seat in a 1998 special election. With nearly every election, however, the seat became more favorable Democrats—including preferring the Democratic candidate for president in every election since 2000—but Wilson still won reelection each time.

In 2006, it appeared the district hit a tipping point. Backlash to the war in Iraq and a number of scandals—including the U.S. Attorneys scandal that Wilson was involved in—as well as a challenge from a high-profile Democrat, Attorney General Patricia Madrid, meant many Democrats thought the district was ripe for a Democratic takeover.

Donors in each party responded. Wilson raised $4.9 million, still a record for one cycle in New Mexico. Madrid herself raised $3.4 million. Both spent virtually their entire campaign warchest in the campaign.

Outside groups also spent large amounts of money. In all, they pitched in $6.54 million.

Candidates and outside groups spent a combined $14.83 million on the race.

When the dust settled, Wilson won by under 1,000 votes, still the closest congressional race in state history.

Wilson, now the Secretary of the U.S. Air Force under President Donald Trump, is no stranger to high-spending races. Her 2004 election campaign against Democrat Richard Romero, which she won, ranks sixth among the most-expensive congressional races and her 2012 Senate race against Martin Heinrich, which she lost, remains the most-expensive federal race in state history.

With campaign finance reports due in December, that record seems poised to fall. And it is already the most-expensive race in the history of the district.

The only other candidate to raise over $3 million in one campaign cycle in the 2nd Congressional District was Harry Teague in 2008. The Democrat won the seat after raising $3.43 million and spending nearly all of it. Teague, however, contributed $1.71 million to his own campaign en route to that number.

Teague is the only Democrat to hold the seat since 1983, when New Mexico earned a third congressional district.

The numbers on spending for federal races are all since 2002, when the McCain-Feingold campaign finance law took effect, but races before then were likely not more expensive.