A Democratic state senator bragged this week about drawing the attention of national Republicans in the competitive race for U.S. Senate in North Carolina. But Erica Smith shouldn’t wear the attacks as a badge of honor. And if Republicans really want to make an impact, they’re going to have to spend a lot more money.

“The @NRSC has purchased a billboard attacking me in Raleigh — calling me ‘too liberal,’” Smith tweeted Monday, referring to the National Republican Senatorial Committee effort. “I am the only candidate that they are spending money against — it shows you who @ThomTillis is worried about. Can’t attack @CalforNC bc no one knows what he stands for.”

Smith was eager to use the billboard as evidence that she’s the most feared challenger to Republican incumbent Thom Tillis, compared to former state senator and Iraq War veteran Cal Cunningham, a fellow Democrat vying for the nomination who has received more national attention.

Tillis is one of the most vulnerable senators this year, with his race rated Tilts Republican by Inside Elections. But Republicans were targeting Smith because they believe she’s the weaker potential general election foe, not because they’re afraid of her.

It’s a page directly out of Missouri Democrat Claire McCaskill’s playbook from her winning Senate reelection campaign from 2012.

“Todd Akin calls himself the true conservative, but is he too conservative? Akin called President Obama a complete menace to our civilization, and has even discussed his impeachment,” one McCaskill radio ad that year said. “Akin wants to stop all funding to Planned Parenthood, outlaw many forms of birth control and Todd calls most government programs socialism, comparing them to a cancer.”

Because the message was delivered by a Democrat to a Republican, it sounded like an attack. But within the context of a Republican primary, the ad could have elevated and solidified Akin’s profile as a conservative to help him secure the GOP nomination. Less than three weeks later, Akin made his infamous “legitimate rape” comment, and McCaskill won reelection by 16 points.

Smith may not be be gaffe-prone like Akin, but she hasn’t been in the same league as Cunningham. Through June 30, Cunningham raised $722,000 and had $683,000 cash in his campaign account. Smith’s “Erica for US” committee raised just $85,000 during the same period and had $25,000 cash left at the end of the quarter.

North Carolina is not the only place where Republicans are trying to meddle in primaries. The NRSC also paid for billboards targeting lower-tier candidates in Colorado (against Stephany Rose Spaulding), Maine (against Betsy Sweet), Georgia (against Teresa Tomlinson) and Iowa (against Kimberly Graham). And Texas Sen. John Cornyn focused early on state Sen. Royce West, rather than Air Force veteran MJ Hegar, who’s already raised $1 million for her campaign.

Even though McCaskill takes (and is given) credit for the strategy, there’s no guarantee that Akin would not have won the primary without the boost from Democrats. But if Republicans want to be successful, they’re going to have to spend more money.

According to McCaskill, her campaign spent $1.7 million before the GOP primary in 2012, and the Democratic Senatorial Campaign Committee spent another $250,000. That hefty spending often gets lost in the stories about strategists wanting to meddle in the other party’s primaries.

Paying for billboards is just a drop in the bucket in the context of multimillion-dollar campaigns, but there’s still time for Republicans to make that splash next year before the primaries. For now, billboards are very unlikely to make the difference in any of these races and are more of an annoyance until there’s more money behind the strategy.

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