Whether Republicans control both chambers of Congress during President Barack Obama’s final two years in office squarely depends on a handful of U.S. Senate races now entering their final phase.
So far in all Senate races, candidates, parties and other political power players have aired more than 428,000 television advertisements, including both primary and general election-focused ads, according to a Center for Public Integrity analysis of data provided by Kantar Media/CMAG, a media tracking service.
Together, the ads are worth an estimated $153 million — a figure that will only continue to balloon between now and the Nov. 4 election.
Candidates themselves are responsible for only about half of these ads. Nominally independent groups — such as super PACs and politically active nonprofits — are responsible for most of the rest.
While partisan primaries in part account for the messaging barrage, candidates and other political groups have aggressively pivoted toward the general election during summer months — traditionally a period of political calm before the post-Labor Day sprint toward Election Day.
To oust Democrats from power, the GOP must pick up six Senate seats in November.
Competitive races are under way in more than a dozen states, with the battlefield stretching from Alaska to Colorado to North Carolina.
Democratic candidates and their allies have aired more TV ads to date than their GOP rivals in Alaska, Arkansas, Colorado, Louisiana and North Carolina, according to data provided by Kantar Media/CMAG.
Republican candidates and their allies, meanwhile, have bankrolled more ads in Georgia, Iowa, Kentucky, Michigan and Montana.
Thanks to retirements of Democratic lawmakers in Montana, West Virginia and South Dakota, the GOP looks poised to pick up at least three seats.
Meanwhile, Democratic incumbents in Alaska, Arkansas, Colorado, Louisiana and North Carolina are bracing themselves against strong Republican challengers.
And hotly contested open seat races are also underway in Iowa and Michigan, where long-serving Democratic senators have also announced plans to retire.
Republicans are mostly playing offense, except in a few states — most notably, Georgia and Kentucky — where Democratic candidates are mounting well-financed bids.
Both Democrats and Republicans have big-money allies on their sides.
Among the five most active non-candidate spenders so far this cycle, three lean Republican and two are aligned with the Democrats.
The top-spending groups to aid Republicans have been Americans for Prosperity, the politically active nonprofit backed by conservative billionaires Charles and David Koch; Crossroads GPS, a nonprofit co-founded by GOP strategist Karl Rove; and the U.S. Chamber of Commerce, a nonprofit trade association.
On the left, the TV ad wars have been dominated by Senate Majority PAC, a super PAC, and Patriot Majority USA, a nonprofit led by a longtime ally of Senate Majority Leader Harry Reid, D-Nev.
So-called “dark money” abounds: Of these five groups, only the Senate Majority PAC must regularly disclose its donors to the Federal Election Commission. The rest must only reveal information about their funders if money is received for a particular ad campaign — something that rarely happens.
Remarkably, about two-thirds of these 428,000-plus ads have aired in just nine battleground states that will likely determine which party will control the upper chamber of Congress during the final two years of Obama’s presidency.