Vidak led 51-49 percent with all precincts reporting but thousands of ballots still need to be counted in the 20th Congressional District, which includes all of Kings County and parts of Fresno and Kern Counties.
Tens of thousands of provisional ballots still to be counted in Fresno County alone.
Neither Jim Costa nor Andy Vidak wished to talk about the election on Wednesday though Costa released this statement, saying "The results of the election continue to come in. There are thousands of votes to be counted. Every vote must be accounted for and we will continue to follow the returns. Obviously, we're still hoping for the best."
Vidak overwhelmed Costa in Kings County, winning 70-percent of the vote. 500 provisional ballots still need to be counted in the area which gave the political newcomer momentum. Tuesday night Vidak said, "I've never done this before so I don't how to compare it to anything but I'm optimistic things are going well."
Costa talked of making up the deficit. He said, "Our strategy was to carry Kern by the margin of our losses in Kings and for Fresno to bring us home."
Kern County supported Costa by a 62-38 percent margin. Kern still has 65-thousand mail-in and provisional ballots to be counted. Roughly a fifth of Kern is in the 20th Congressional District.
Costa won Fresno County by a similar margin 61-39 percent. 25-percent of Fresno County voters are in the 20th District.
ABC30 Political Analyst Tony Capozzi said Costa may now have a slight edge with so many ballots out in both Kern and Fresno counties. Capozzi said, "People forget that there are many thousands of provisional ballots out there and they're not counted until sometimes two weeks after the election and that may make the difference in this case."
Costa-Vidak still too close to call. The next ballot update on this race will come on Friday.