Clint Olivier, a first-term Fresno City Council member who last year decided to explore a congressional run against incumbent Democrat Jim Costa, said Tuesday he was ending his candidacy.

Olivier, 36, is the latest in a long line of name Republicans to either reject or abandon a run for the newly created 16th Congressional District, which includes about half the city of Fresno, parts of Fresno and Madera counties and all of Merced County.

Most recently, Hanford Republican Andy Vidak -- who nearly upset Costa in 2010, but in Costa's old district, which ran from Fresno south through Kings County to Bakersfield -- expressed interest in a rematch.

But he, too, said Tuesday he won't run.

Jeffrey Cummins, a political science professor at California State University, Fresno, said political reality may be hitting home for Republicans.

"I think it's just the usual impact of having a longtime incumbent in the district who is very experienced and an effective fundraiser," he said.

Cummins also thinks an improving economy may be tempering some early Republican optimism for gaining seats in Congress. Republicans have to defend several California seats, there are other Democratic districts in the state that are more vulnerable than Costa's -- and there is only so much money to go around -- he said.

Before Olivier and Vidak, Merced County Sheriff Mark Pazin, Clovis businessman Case Lawrence and former Fresno Mayor Jim Patterson, among others, considered and then decided against challenging Costa.

Olivier said in a written statement that the "difficult decision was made after much prayer and contemplation.

"As we face the possibility of more painful cuts to city services this year, I feel the need to dedicate 100% of my time and effort to finding innovative ways to get the City of Fresno through this critical period. Doing so will leave me no time for a grueling congressional campaign."

Olivier said he will close his exploratory committee after returning unused funds to donors.

The departure of Olivier and Vidak's decision to pass on a rematch leaves local attorney Brian Whelan, 28, and dairyman and business owner Johnny Tacherra, 36, of Burrel, which is just west of Riverdale, as the two remaining Costa rivals.

Both say they will definitely take on the fourth-term Democrat from Fresno, who Republicans continue to insist is vulnerable -- especially this year, when districts across the state have been redrawn based on new U.S. Census numbers.

But the Cook Political Report, a respected nonpartisan analyst, and University of Virginia political science professor Larry Sabato's "Crystal Ball" both rate the 16th District as "likely Democratic."