The increasingly heated fight over health-care legislation is saturating the summer airwaves, with groups on all sides of the debate pouring tens of millions of dollars into advertising campaigns designed either to push the cause of reform forward, slow it down or stop it in its tracks. Drug makers, labor unions, both national parties and the sector currently under the heaviest fire -- health insurance companies -- are all weighing in with significant ad buys. Nationwide, more than $52 million has been spent this year on health reform-related ads, according to the Campaign Media Analysis Group, setting the stage for what may be a record-breaking legislative battle. 'This has the potential to certainly be the biggest (ever) as far as an advocacy advertising campaign goes,' said Evan Tracey, CMAG's chief operating officer. Much of the spending has been focused on national cable news and the local Washington market, the best way to reach policymakers and opinion leaders in the capital. But as members of Congress head home for August, advertising dollars are following them, as the target audience for health-care messages shifts from inside to outside the Beltway. While viewers in key states have seen 'a steady trickle' of ads all year on issues like the economic stimulus package and the climate change bill, Tracey said, 'The faucet's going to be a little wider on health care because there are so many different stakeholders, and so much opposition, and it's such a big issue.' Nevada, the home state of Senate Democratic Majority Leader Harry Reid, is one of a handful of states that have witnessed a disproportionate share of ads. Tracey's group calculates that, as of Tuesday, Las Vegas was the single-biggest health-care ad market so far this year, both in terms of local television spots aired (716) and money spent ($315,000). Bismarck, N.D., was second in ads aired, followed by New Orleans; Portland, Maine; Helena, Mont.; Reno and Fargo, N.D. Each state has good reason to be on the list: Louisiana is the site of a competitive 2010 senate race, while Maine, Montana and North Dakota are home to key senators on the Finance Committee. Of the $52 million spent so far, CMAG calculates that the largest share -- $23 million -- has come from groups advertising broadly in favor of overhauling the health care system, without necessarily positioning for or against the plans being advanced by Obama and congressional Democrats. The Pharmaceutical Research and Manufacturers Association has joined the nonprofit group Families USA to spend roughly $4 million airing an updated version of the iconic 'Harry and Louise' ads, but this time the couple is calling for passage of reform. The drug industry group has more advertising planned for August. 'Most of it will come in targeted congressional districts where our companies have a significant economic presence, or in districts where members (of Congress) can still be persuaded to support comprehensive health-care reform,' said PhRMA spokesman Ken Johnson. America's Health Insurance Plans, a trade group representing insurance companies, is currently running what it calls a 'seven-figure buy' on national cable of its first ad of the year, calling for health care to be 'as affordable as possible' and 'supporting bipartisan reforms that Congress can build on.' The ad comes as congressional Democrats focus their message on the alleged misdeeds of insurance companies; Speaker Nancy Pelosi, D-Calif., last week called them the 'villains' of the health-care fight. Karen Ignagni, AHIP's president and CEO, complained Tuesday that while 'the country should be in the midst of a transformative national conversation about health reform, instead a campaign has been launched to demonize' the insurance industry. In August, Ignagni said, AHIP will remain focused on spreading the message -- via the existing ad campaign and other efforts -- that the group supports reform. In the opposite corner is the liberal group Americans United for Change, which launched an ad this week asking, 'Why do the health insurance companies and Republicans want to kill President Obama's health insurance reform?' The spot criticizes the huge pay packages and 'golden parachutes' of insurance company CEOs. The ad campaign is running on national cable stations, with additional rotations on Washington, D.C. cable, for a modest total buy of roughly $10,000. 'We anticipate using paid media throughout August both in the states and nationally as necessary,' said Americans United spokeswoman Lauren Weiner. Organizing for America, the grass-roots arm of the Democratic National Committee, is planning a larger offensive this month. In July, OFA ran a pro-reform television ad, 'It's Time,' in more than 20 local media markets, and is currently airing a national cable spot highlighting 'the cost of doing nothing' on reform. Organized labor is also spending heavily in support of Democrats' reform plans. In the second half of July alone, AFSCME ran at least four different health-care ads aimed at 14 different members of the House and Senate, with a roughly even split between Republican lawmakers and Democrats who are wavering on whether to support reform. The labor organization plans to continue the drumbeat this month. 'We spent over a million dollars in the past three weeks, and it's fair to say we're going to invest substantial resources in television advertising in August,' said Chuck Loveless, AFSCME's director of legislation. He added that the group hadn't finalized its list of targets for this month, but 'it's fair to say it will be a mix of Republicans and Democrats.' So far, spending in favor of Democratic reform plans ($17.4 million) has dwarfed spending in outright opposition ($8.1 million), according to CMAG, as some groups in the latter camp have been holding their fire until more details of the proposed bills begin to emerge. The conservative group Americans for Prosperity spent more than $300,000 last week on a national and D.C. cable spot asking members of Congress, 'Did you read the bill' before you voted for it? The group hopes to have more ads on the air in August but would not elaborate on their specific plans. The U.S. Chamber of Commerce is running print ads aimed at protecting the employer-provided health care system in Maine, Louisiana and North Carolina. 'We plan to expand to TV and radio,' said Chamber spokeswoman Blair Latoff, but the details haven't been finalized. After running television spots last month in three states -- Nevada, North Dakota and Arkansas -- the Republican National Committee is currently airing radio ads in 60 congressional districts in 33 states. The RNC is launching new radio ads this week in the districts of four 'Blue Dog' Democrats: Reps. Zach Space of Ohio; Baron Hill of Indiana; Bart Gordon of Tennessee and Mike Ross of Arkansas. All four voted in favor of the Energy and Commerce Committee's reform bill last week. Overall, the RNC is spending close to $1 million on a broad health-care campaign that includes TV and radio ads as well as 'tele-town hall' meetings and a new Web site mocking the Obama reform 'experiment.' On the left, MoveOn.org is on the radio, airing ads in the districts of three other conservative Blue Dogs who voted against the Energy and Commerce reform measure -- Reps. John Barrow of Georgia, Jim Matheson of Utah and Charlie Melancon of Louisiana. The Democratic Congressional Campaign Committee is also using radio, running 'drive-time' spots against seven GOP lawmakers accusing them of 'siding with insurance companies' against reform. Staff writer David Hilzenrath contributed to this report. 