Total amount expected to be spent on the 2018 federal midterm elections, making them the most expensive in history: $5.2 billion

Previous spending record for a midterm election: $4.2 billion

Percent by which spending increased over the 2014 midterm election cycle, marking the most dramatic jump in at least two decades: 35

Amount by which Democratic candidates are expected to outspend Republicans this cycle: $300 million

Amount that outside groups unaffiliated with candidates or parties have spent so far at the federal level, with most of that going toward negative TV ads: $1.1 billion

Spending to date this cycle by secret-money groups that don't disclose their donors to the Federal Election Commission: $128 million

Decline that represents over the last midterm election, with more money instead being funneled through super PACs and other outside spending groups that only partially disclose donors: 28

Amount of secret money spent so far on the U.S. Senate races in Florida and Tennessee, which have been subject to the greatest such influence: $10 million

Rank of the 2018 U.S. Senate race in Texas among the highest-spending Senate races in history: 1

Record-breaking amount raised by Beto O'Rourke, the Texas Democratic congressman who's challenging Republican U.S. Sen. Ted Cruz: $61.8 million

With O'Rourke declining contributions from political action committees, percent of his take that came from small individual contributions of less than $200, the fourth-highest of any Senate candidate: more than 46

In the 30 U.S. House races CNN has identified as toss-ups this year, including contests in Florida, Kentucky, North Carolina, Virginia, and West Virginia, total amount contributed to Republican candidates: $90.7 million

To Democratic candidates: $166.8 million

If the Democrats win the U.S. House, rank of campaign finance reform among the top issues current House Minority Leader Nancy Pelosi (D-California) says she plans to tackle: 1

Chance that politics website 538.com gives the Democrats of winning the House: 6 in 7

Chance it gives them of winning the Senate, where current Majority Leader Mitch McConnell  (R-Kentucky) is a strong defender of big money in politics: 1 in 7

(Click on figure to go to source.)