It’s not your imagination: Three weeks before election day, the political air wars are heating up. Here at the Sunlight Foundation, where we track ad spots by politically active committees for our AdHawk mobile app, we counted 48 new ones on Tuesday alone.

By far the majority are attack ads by outside groups; their placement gives a good hint about where the political “smart money” sees the nation’s most truly competitive races in the homestretch of campaign 2014. Some of the highlights.

Statewide races

In South Dakota, where a four-way Senate race merited front-page coverage in Tuesday’s New York Times, there’s an effort underway to shore up beleaguered Republican frontrunner Mike Rounds, the state’s former governor. The American Chemistry Council, whose extensive political efforts we’ve catalogued in this space, has produced a pro-Rounds ad. And while Rounds refuses to run negative ads, that’s not stopping the National Republican Senatorial Committee, which has produced a spot attacking his two top opponents, Democrat Rick Weiland and former Sen. Larry Pressler, a Republican-turned-independent.

In Kansas, another state where a multi-candidate race is making Republicans nervous, the U.S. Chamber of Commerce is attacking independent Greg Orman as a closet Democrat, citing, among other things his refusal to endorse the Keystone XL pipeline or speak out against the President Barack Obama’s health care law.

The National Rifle Association is wading into gubernatorial races, posting ads calling for the defeat of Democrat Maggie Hassan in New Hampshire and the reelection of Republican Gov. Nathan Deal in Georgia. That’s on top of an ad the NRA posted on Monday attacking Colorado Gov. John Hickenlooper, D, who is running for a second term.

Keeping up the negative drumbeat, the National Republican Senatorial Committee released ads Tuesday attacking two of the nation’s most vulnerable Democratic senators, Mark Pryor of Arkansas and Mark Udall of Colorado, as well as Rep. Bruce Braley, an Iowa Democrat vying to succeed retiring Sen. Tom Harkin, D-Iowa.

Political heavyweight American Crossroads adapted the much-commented upon spelling bee ad it used against Pryor in Arkansas to target Jeanne Shaheen in New Hampsire on top of a new message targeting Sen. Mark Begich, D, in Alaska. Meanwhile, dark money partner Crossroads GPS goes after Sen. Mary Landrieu, D, in Louisiana.

AFSCME, the public employees’ union, fired back with new negative ads slamming Republican Senate candidates in Colorado, Iowa and North Carolina.

House Races

In Maine, the Tea Party-aligned FreedomWorks unveiled a spot touting Bruce Poliquin a Republican running in the state’s 2nd Congressional District, and another painting his Democratic opponent, Emily Cain, as a far-left Obama devotee.

The Democratic House Majority PAC, meanwhile, issued ads attacking Republican congressional candidates in California’s 7th Congressional District, New York’s 18th Congressional District.

American Action Network and its affiliated super PAC, the Congressional Leadership Fund, answered back with ads attacking Democrats in California 7th one of that state’s most competitive contests and Rep. Ron Barber, D, in Arizona’s Second District, a swathe of land on the Mexican border that Stuart Rothenburg calls a pure toss-up.

The Congressional Leadership Fund, the AAN’s super PAC, unleashed new spots in a trio of House races: Opposing congressional hopeful John Foust in Va., and incumbent Reps. Scott Peters in California and Brad Schneider in Illinois.

On a positive note

That’s not to say it’s been entirely attack and burn in the political ad world. The pro-gay rights GOP group American Unity PAC is running positive spots on behalf of GOP congressmen Chris Gibson in NY-19 and Frank LoBiondo in NJ-02. Meanwhile the United Mine Workers PAC just released a pro-Allison Lundergan Grimes ad in Kentucky, where coal is always near the top of the agenda and the House Majority PAC, headed by a former DCCC operative, has just put out a glowing review of Rep. Kyrsten Synema, D-Ariz., and her “eagerness to work across the aisle to promote Arizona issues.”