Backed by prominent fiscal conservatives such as Sens. Jim DeMint (R-S.C.) and Mike LeeMichael (Mike) Shumway LeeNSA spying program overcomes key Senate hurdle With religious liberty memo, Trump made America free to be faithful again This week: Time running out for Congress to avoid shutdown MORE (R-Utah), Stenberg is positioning himself as a more conservative alternative to Bruning, the race's front-runner.

Although Stenberg's campaign hasn't been on the air until now, this isn't the first that television watchers in Nebraska have seen of Stenberg. Two fiscally conservative groups backing Stenberg — the Club for Growth and DeMint's Senate Conservatives Fund — have both aired ads supporting him.

A third outside group, Americans for Prosperity, is on the air with ads attacking former Sen. Bob Kerrey (Neb.), the Democratic recruit to replace retiring Sen. Ben Nelson (D). Meanwhile, the two other Republicans in the race — Bruning and state Sen. Deb FischerDebra (Deb) Strobel FischerUS trade deficit rises on record imports from China Flake, GOP senators to meet with Trump on trade Senate nixes provision boosting conservative college after uproar MORE (R) — have both gone up with ads of their own.

The Hill rates this race as leaning Republican.

Watch the ad: