LAS VEGAS — Two Democrats running in competitive Nevada House races said they each raised nearly $600,000 last quarter, touting their respective hauls as encouraging signs in their quest for Congress.

State Sen. Ruben Kihuen announced Friday that he raised more than $570,000 in the quarter that ended Sept. 30. He’s running against freshman incumbent Republican Rep. Cresent Hardy in a Democratic-leaning district.

Campaign manager Dave Chase said the “enthusiastic support” for Kihuen’s bid shows voters are ready for a change from the conservative Hardy. Chase also jabbed at the Hardy campaign’s lack of TV commercial reservations during the crucial last weeks of the campaign.

“We can only assume that Congressman Hardy expects Washington Republicans and billionaire-backed super PACs to swoop in and try to drag him to victory,” Chase said.

Hardy’s campaign says it will release fundraising numbers on the Oct. 15 deadline and denies that the lack of TV reservations is a cause for concern.

Campaigns are just one of the groups that buy TV airtime, which gets more expensive as Election Day approaches. National party committees and outside PACs often get involved.

In addition to a gauzy, mostly positive commercial from the Hardy campaign that portrayed him as eager to serve his constituents, the National Republican Congressional Committee is funding negative spots associating Kihuen with “sleaze.”

Congressional campaigns must also decide whether TV is the most cost-effective route for reaching their audience. Commercials in the Las Vegas TV market reach voters in three congressional districts — an efficient route for candidates running statewide races, but a partial waste for candidates who only need to talk with a subset of the market.

Meanwhile, Democratic House candidate Jacky Rosen announced she raised over $580,000 last quarter for her bid in southern Nevada’s 3rd Congressional District. The political newcomer has been running ads introducing herself as a pragmatic former computer programmer who helped her synagogue go solar, but also attacking her Republican opponent Danny Tarkanian over Social Security.

Rosen campaign manager David Furr also raised questions about Tarkanian’s recent TV ad reservation cancellations, suggesting they were trouble signs.

Tarkanian, who’s lost several previous bids for office, is now seeking to represent a swing district that’s been held by his party for the past three cycles. His campaign isn’t yet releasing fundraising details but responded to concerns about going dark on TV.

“We have a strategy to communicate to the public about Danny Tarkanian’s independent-minded solutions to the problems that face southern Nevada,” said his campaign manager, Jonathan Gormley, about the reservation cancellations. “We’re pursuing that strategy.”