As Romanoff narrates, a graph of the nation’s soaring debt pops up on the screen. The image looks strikingly similar to one that appears in a Web video Wisconsin Rep. Paul Ryan released in 2011 to sell his controversial budget plan, though a Romanoff spokeswoman insisted that the campaign hadn’t borrowed from the former GOP vice presidential contender.

New Hampshire Rep. Ann McLane Kuster, whose district broke for Obama by a yawning 11-percentage-point margin in 2012, is running an ad that touts her support for small-business tax cuts while showing her touring a local microbrewery. Separately, former Iowa state Sen. Staci Appel, in a district Obama won by 4 percentage points two years ago, underscores her record of fighting overspending in state government, a populist theme often heard from tea party-aligned conservatives.

Democratic Rep. Ron Barber, in a swing southern Arizona district that is slightly more conservative than the others, uses his first TV spot to highlight his support for increasing border security funds. The ad — complete with the image of a border patrol car — doesn’t mention elements of immigration reform that are typically more popular among Democratic voters.

Like the commercials aired by Romanoff, Kuster and Appel, Barber’s doesn’t mention his Democratic Party affiliation.