(CNN) -- Republican Rep. Todd Akin isn't budging. Despite calls from his party establishment to drop out -- including a personal phone call from vice presidential hopeful Paul Ryan -- Akin said Wednesday, August 22nd he is staying in the U.S. Senate race.
"The people of Missouri chose me to be their candidate. And I don't believe it's right for party bosses to decide to override those voters," he said on ABC's "Good Morning America."
Ryan "did give me a call, and he felt that I had to make a decision, but he advised me that it would be good for me to step down," Akin said on NBC's "Today Show."
He said he told Ryan "that I was going to be looking at this very seriously, trying to weigh all the different points on this," adding, "it's not about me -- it's about standing on principle."
GOP presidential hopeful Mitt Romney also has called for Akin to step aside.
But Akin let a Tuesday deadline to do so easily go by.
On Twitter, he asked supporters, "Will you chip-in $5 to help me fight the party bosses?" And he linked to an image showing a red Missouri and the words, "Let the people decide not party bosses."
Akin operates in "an insular environment," with his wife and son serving as his top advisers, a senior Republican source told CNN. Republican leaders have concluded that Akin "lives in a parallel universe," the source added.
Akin is facing Democratic Sen. Claire McCaskill. Republican leadership had hoped to pick up the seat in November, but the fury over his remarks on rape and pregnancy, which came during an interview Sunday, has thrown that effort into jeopardy.
The GOP was counting on winning Missouri in hopes of gaining the majority in the Senate, Republican officials say.
Now, Republican leadership has vowed not to spend money on his candidacy, as have outside groups supporting Republicans.
The National Republican Senatorial Committee had $5 million reserved for the Missouri race and told Akin it will pull the funds if he stays in, a committee source told CNN.
"We saw this as an eminently winnable Senate race," said Steve Law, head of American Crossroads, the super PAC backed by Republican operative Karl Rove. "There were great issues to talk about. We were talking about Obamacare, and taxes, and debt and the economy. But this firestorm that Todd Akin has created for himself has engulfed not only him but, we think, any chance whatsoever of being able to salvage this race as long as he's in this race."
McCaskill has rejected Akin's controversial comments and highlighted them on her campaign website. "Her worst nightmare is him dropping out," Law said, because with Akin as her opponent, "she can win."
Although Akin blamed "the liberal elite" and "the liberal media" for his troubles in a slew of tweets, he acknowledged Wednesday that it's his own party -- including prominent conservative media figures such as Sean Hannity and Rush Limbaugh -- calling for him to drop out.
His insistence on keeping his candidacy came on the third day of a national -- and even international -- uproar, which shows no sign of dying down. While he has apologized for his incendiary and inaccurate comments, many question how a major-party Senate candidate, who serves on the House science committee, could say such things to begin with.
Speaking to Missouri television station KTVI on Sunday, Akin explained his opposition to abortion being legal in the case of rape. "From what I understand from doctors, that's really rare," he said of rape-induced pregnancy. "If it's a legitimate rape, the female body has ways to try to shut that whole thing down."
He has since repeatedly said that there is no such thing as "legitimate rape" and that his medical information was wrong.
Asked Wednesday by NBC whether he is "almost alone" now, Akin said, "I don't believe that's true."
"Anybody who's doing a lot of public speaking can make a mistake," he added. "You say you're sorry. You put the politics aside and you do what's the right thing."
"At the same time, I don't apologize for the fact that I'm consistently pro-life," he said on ABC. "I believe in defending the unborn. And I believe, based on those kinds of principles, we can win this race."
Asked whether he may still bow out before another deadline in late September, Akin said he doesn't "know the future."
Under Missouri law, he could withdraw by September 25, but would need a court order and would have to cover any costs for ballots that had already been printed. The state Republican committee would then choose a replacement candidate.
Akin said Wednesday he is honoring his party's wishes in one key way.
Reince Priebus, chairman of the Republican National Committee, does not want him to attend next week's Republican convention. Akin said he won't attend. "I honor their particular wishes," he told ABC.
Akin is a devout evangelical Christian who believes God has called on him to run, Republican sources say.
Throughout his career, he has lacked the support of the party establishment and succeeded without it, so the lack of support now doesn't faze him as it would many others, a senior Republican source said.
GOP officials will keep a close eye on the race in Missouri to see if he is able to raise money. The question will be whether the congressman finds enough grass-roots support to sustain his campaign, the source said.
The controversy surrounding him also distracts from the issues the GOP would rather focus on, specifically the economy.
Instead, it draws attention to the issue of abortion, and the official Republican Party platform -- ratified this week -- which mirrors Akin's position that abortion should be illegal even in the case of rape. That focus also highlights a schism within the party. Romney, among many other Republicans, supports exceptions for rape and incest.