Why Donald Trump's New Television Ad Buy Could Be Too Little, Too Late

Hillary Clinton has been dominating the airwaves in battleground states.

With outside groups excluded, the Clinton campaign outspends Trump's more than a 9 to 1, according to a new ABC News analysis of television advertising data from CMAG/Kantar Media.

Trump announced a $10 million ad buy earlier this week, which is his largest yet of this election cycle. But as of midday Friday, just half that amount had been reserved on the airwaves, according to CMAG.

Meanwhile, Clinton's campaign and the behemoth super PAC supporting her continue to dump big money into broadcast spending, taking full advantage of her three-month head start.

The Clinton campaign is responsible for almost two-thirds of pro-Clinton spending on the airwaves, while Trump's campaign is responsible for not even one-third of pro-Trump television ad spending.

Clinton's campaign has spent $84.0 million on general election ads this cycle, compared with just $8.9 million to date for the Trump campaign. The main super PAC backing Clinton, Priorities USA Action, has spent $44.0 million so far, compared with only $12.8 million from the highest-spending super PAC supporting Trump, Rebuilding America PAC.

Clinton is outspending Trump in every state by wide margins. She's focusing on Florida and Ohio, both must-win states for Trump if he is to reach the White House. She's also spending significant sums in North Carolina, Pennsylvania and Nevada.

You can find a full list of battleground states and spending in the tweet linked below. These numbers do not include a recently announced buy from Clinton in Arizona, a state that has gone Democratic in only one presidential election since 1952.

The Clinton campaign is no longer spending any money in Colorado or Virginia but continues to ramp up spending in Florida, Ohio and North Carolina. These are signs that Clinton is going on the offense, winding down spending in states she has in her grasp while dumping money into three states, any one of which in her column would likely block Trump's path to the White House.

And the chart linked below demonstrates the importance of certain states to the Clinton campaign by showing how much it has spent in each per electoral vote.