Hillary Clinton tours a T-shirt shop in Des Moines this month. (Melina Mara/The Washington Post)

Hillary Clinton has reserved nearly $80 million in additional television advertising across eight key states in coming months, according to a senior aide, offering both a window into how the Democrat sees the presidential contest shaping up and a reminder of her dominance on the airwaves in the the race against Republican Donald Trump.

The new ad reservations include $3 million more for the remainder of August and nearly $77 million for September and October in the eight states, the aide said. The campaign is targeting Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio and Pennsylvania. In addition, Clinton is continuing to advertise in the Omaha market in Nebraska, one of only two states that awards its electoral votes based on performance in congressional districts.

The Trump campaign, by contrast, launched its first general-election TV ad last week, saying it planned to spend $4.8 million on a 10-day buy in four states: Florida, North Carolina, Ohio and Pennsylvania.

The Clinton aide spoke on the condition of anonymity to share campaign strategy more freely.

The disparity in TV ads reflects fundraising by Clinton that until recently had been far more robust than that of Trump, as well as a strategy by Trump to generate more exposure through television interviews and social media.

Before the new buys, Clinton’s campaign said it already had spent $70 million on TV ads in targeted states, not including other ads running nationally on cable. Clinton also is planning to air $15 million in radio ads in the fall, the aide said.

The advertising targets underscore which states the respective campaigns consider to be in play. The four that Trump is targeting are viewed as essential to his path to victory, while Clinton is investing in more battlegrounds than she necessarily needs to reach the requisite 270 electoral votes on Nov. 8.

Back in mid-June, when Clinton began her first general-election ads, she also went on the air in Colorado and Virginia, two states from which she pulled back advertising amid growing confidence that the states are winnable for her.

In Virginia, Clinton has a 14-point advantage, according to a Washington Post-ABC News poll published last week. Some recent surveys in Colorado also have shown Clinton with a double-digit lead over Trump.

The Clinton aide stressed that targets and spending levels could continue to change as the race evolves.

An ad put out by Hillary Clinton's presidential campaign uses Republican rival Donald Trump's own words to suggest that he would be dangerous as president. (Hillary Clinton)

The latest Clinton ad set to air in the battleground continues a well-established theme for her campaign: that Trump is unfit to lead the nation. The new spot uses some of Trump’s own words to suggest that he would pose a danger as commander-in-chief.