Rep. Devin Nunes (R-Calif.) is mulling a run against Sen. Dianne Feinstein (D-Calif.).

Nunes has been running ads in his congressional district slamming Feinstein. When asked by a local newspaper whether he would challenge the longtime senator, he said it was a possibility.

"Could it be me? Sure," he said. "There would have to be a lot of things to fall in place."

Whoever runs against Feinstein will have an uphill climb. California is a blue state that has only become more Democratic in recent years, partly due to its growing Hispanic population. Democrats won hotly contested elections for the Senate and governorship last year despite a strong year nationally for Republicans. On top of that, Feinstein is somewhat centrist, giving her crossover appeal to the state's independent voters.

Nunes is known as a sharp-tongued conservative, although he is more of a centrist on some social issues. If he runs, he would give the GOP a solid recruit against Feinstein, although he would start off as a long shot.