Washington (CNN) -- New Jersey Gov. Chris Christie opted for a special election to fill a newly vacant Senate seat through 2014 instead of appointing a replacement through that time, saying the decision was about giving voters "a choice and a voice in the process" and was not driven by political self-interest.
While the Republican's decision for a special October ballot could help him avoid stronger Democratic turnout in his re-election bid a month later, it also opens him up to criticism from his own party that is on the short end of the balance of power in the Senate.
Christie explained his decision one day after the Garden State's senior senator, Frank Lautenberg, a liberal Democrat, died at 89 after an illness. Christie said he would name a placeholder as soon as possible to fill the seat until the October election.
Democrats immediately slammed the move, asserting that Christie is wasting taxpayer money to protect his ambitions. National Republicans weren't critical but they didn't praise the governor, either.
Christie announced that Democratic and Republican primary elections will be held on August 13 with the general election on October 16.
The winner of the special election will serve out the final year of Lautenberg's term, and an election for a full six-year term will occur the following November.
Voters should have say
While Christie said state law allowed him to name a replacement for the remaining year-and-a-half of Lautenberg's term, he believes an appointment over that period of time was not suitable or fair.
"The issues facing the United States Senate are too critically important and the decisions that need to be dealt with too vital not too have an elected representative making those decisions who was voted on and decided on by the people of this state. These decisions should be made by an elected official who represents the will of voters of New Jersey," Christie said.
The expense of an election is also an issue during an era of belt tightening.
The New Jersey Office of Legislative Services, an administrative wing of the Democrat-controlled state Legislature, estimates it will cost $12 million to state taxpayers to conduct a primary and another $12 million for a general election.
New Jersey is already voting in a general election on November 5, when Christie is bidding for a second term. So some ask why doesn't he save $12 million and schedule a special general election a few weeks later?
Christie said state law only permits the option of an October special election or an election in 2014.
Christie said "there's no political purpose" behind his decision on the election date.
But polls show that he has a 2-1 advantage over state Sen. Barbara Buono, his Democratic challenger. And putting a special Senate election on the same day in November would most likely increase Democratic turnout, especially if Newark Mayor Cory Booker is on the ballot. Booker was considering his own run for Senate in 2014.
By placing the special Senate election in October, Christie avoids Democratic turnout tied to this issue possibly becoming a problem for him.
National Democrats quickly blasted the decision.
"Governor Christie might not know or care how many millions of taxpayer dollars his special election gambit will waste, but the people of New Jersey certainly do. Christie should do the right thing, protect New Jersey taxpayer dollars instead of his own political career, and hold the Senate election on the same day as his own," Democratic Governors Association Executive Director Colm O'Comartun, said in a statement.
Christie said that the costs associated with special primary and general elections "cannot be measured" against the value of an elected senator "when so many consequential issues are being debated and determined this year."
State Democrats had threatened legal action if Christie pushed the election back to November 2014, but Christie's not sure if his decision averts a legal challenge, adding, "In New Jersey, people sue over everything."
Christie said he has yet to decide on a placeholder. But he said he has a list in his head and that he'll make a determination relatively soon.
"I'm looking for a person who's going to be a good United States senator," he said.
The outspoken governor also said it wouldn't be fair to appoint a GOP placeholder to serve out the remainder of the late Democratic senator's term.
"I understand the political advantage that would come to me if I was the person, the sole person, to decide who would be in the Senate representing New Jersey for 18 months, but I just did not feel comfortable doing that," he said.
Christie didn't say at the news conference whether the placeholder will be allowed to run in the special election, but a source close to the governor told CNN, "Legally the appointee could run if he or she wanted to, but would have to go through the election process."
Republicans not praising Christie
National Republicans weren't criticizing Christie's decision, but they weren't praising it, either.
"I am sure the governor exercised whatever option he had in the best interest of his state and I won't question the path that he has chosen," Senate Minority Leader Mitch McConnell said.
Christie's decision could complicate his already-strained relationship with national conservatives, which could spell trouble if he decides to run for president in 2016.
"I was disappointed he didn't pick a Republican to fill out the rest of the term, but not surprised," said Katon Dawson, the former Chairman of the South Carolina Republican Party.
"Chris Christie has always done what's best for Chris Christie in New Jersey," added Dawson, whose state is traditionally one of the first to cast ballots in the presidential primary process.
Many on the right are still upset with Christie's praise of President Barack Obama personally and the federal response in the wake of Superstorm Sandy, just days before last November's presidential election.
While Christie's approval rating in New Jersey soared after Sandy and has remained high, some commentators in his own party blasted him for his praise of Obama, saying it contributed to the defeat of GOP nominee Mitt Romney.
And Democrats were quick to point that out.
"Republicans have not won a Senate race in New Jersey in more than 40 years. Their only shot was an appointee who had a year and a half to establish themselves before an election in 2014," Democratic Senatorial Campaign Committee Deputy Executive Director Matt Canter said. "With this news, I assume operatives at the NRSC are busy planning Christie's defeat in Iowa and New Hampshire right now."
Meanwhile, the rival National Republican Senatorial Committee pointed toward what could be a divisive Democratic primary.
"Democrats will now face an ugly primary sprint between Cory Booker, Rob Andrews and Frank Pallone -- all with substantial war chests and a healthy dislike for each other," NRSC spokesman Brad Dayspring said. "Corey Booker did not want to have to wrap this up in two months."
Democratic Congressman Rush Holt may also make a bid for the Senate seat.
CNN Senate Producer Ted Barrett contributed to this report.