Republican Senate candidate Richard Mourdock pauses as he speaks to supporters Tuesday in Indianapolis. (Darron Cummings/AP)

Democrats scored decisive Senate wins in Missouri and Indiana after candidates supported by the tea party and evangelical Christians made controversial remarks on rape, pregnancy and abortion that appeared to cost them the support of more-moderate voters in their party.

Rep. Todd Akin, who had been favored to win the Senate seat in this Republican-leaning state before his statements on “legitimate rape” triggered widespread national scorn, conceded victory to Sen. Claire McCaskill. In his concession speech, Akin thanked God, who, he said, “makes no mistakes.”

Akin struck a combative, anti-Washington tone in the speech, calling for smaller government and excoriating the Obama administration for its handling of an attack on a U.S. diplomatic post in Libya. He said it was “inexcusable” for the president “to betray fellow Americans to terrorists when they could have been rescued.” Senior Pentagon and CIA officials have said repeatedly that they did not have forces in place that could respond fast enough to halt the attack on the post in Benghazi.

Akin ended his speech by praising supporters who had bucked calls from Republican Party leaders for him to abandon his candidacy after his rape remarks. “Washington doesn’t need more money, it needs more courage,” he said.

The Missouri race was echoed in Indiana, where Democrats picked up a Senate seat with the victory of Rep. Joe Donnelly over Republican Richard Mourdock. Mourdock’s campaign stumbled badly after he said in October that pregnancy resulting from rape was “something God intended.”

His remarks did not bring the same kind of wide condemnation as Akin’s, but they appeared to shift the race to Donnelly.

The tea party-backed state treasurer had handily won the Republican primary over Sen. Richard G. Lugar, a six-term moderate. Ten days after his pregnancy remarks, polls showed Mourdock trailing Donnelly by 11 points.

The remarks turned the two races into touchstones in this year’s gender battles. The results, in states that the Republicans had long counted on, helped ensure they would not win the four seats needed to retake the Senate majority from Democrats.

Akin’s troubles began in August, when he defended his staunch opposition to abortion, even in cases of rape and incest, and insisted in a TV interview that pregnancy in cases of “legitimate rape” was rare because women’s bodies were able to prevent it.

“From what I understand from doctors . . . if it’s a legitimate rape, the female body has ways to try to shut that whole thing down,” Akin said.

Top Republicans, including presidential nominee Mitt Romney, tried to drive Akin from the race, demanding that he quit and denying him millions of dollars in promised campaign funds. GOP officials were gambling that distancing themselves from Akin, who had become something of a national laughingstock, would give them a better chance of winning the presidency as well as seats in other close Senate races.

McCaskill spent four times as much as the underfunded challenger, portraying him as an extremist who wanted to abolish the minimum wage, end federally subsidized school lunch programs and eliminate federally backed student loans.

Akin’s “legitimate rape” comments were a political gift to the Democrats. In the final days of the campaign, McCaskill’s ads featured Romney condemning the remarks as “offensive” and urging Akin to step out of the race.

After he was cut off from the backing of his party, Akin appealed for grass-roots support from Missouri’s large evangelical Christian population — as much as a third of the electorate, according to some estimates — who were his most fervent backers in the primary.

Those supporters crowded his election gathering Tuesday night, which began with a prayer, the Pledge of Allegiance and the singing of both the national anthem and “God Bless America.” The prayer was led by the head of a conservative women’s group that had formed to support Akin.

At McCaskill’s headquarters, campaign officials were buoyed early on by a reported heavy turnout in the larger urban areas, including some lines in which voters waited more than three hours to cast ballots. To ensure that the voters stayed on through the cold, rainy weather, McCaskill campaign officials supplied them with hot chocolate and granola bars.

“We had some supplies ready, but the turnout has been remarkable,” said Caitlin Legacki, the communications director for McCaskill’s campaign.

Akin, 65, a former seminary student who home-schooled his children and placed his religious beliefs at the center of his run for office, also relied heavily on the support of Mike Huckabee, the former GOP presidential candidate and Arkansas governor, who described him in ads as a “good man with a Christian heart.”

As he appeared to make up lost ground in the final days of the race, Akin drew some support from more-mainstream Republican groups that had spurned him. A right-leaning super PAC spent about $1 million on ads urging Romney supporters to back him, and state party coffers swelled with about $700,000 earmarked for Akin’s candidacy.

Most of the ads pilloried McCaskill for supporting President Obama’s health-care initiative and the federal stimulus act.

A first-term senator who in 2006 had defeated incumbent Republican Jim Talent — now a top Romney adviser — McCaskill was attacked as a creature of Washington whose husband had reportedly received million of dollars in federal housing subsidies. McCaskill described one ad, which alleged that her husband had closed a business deal in the Senate dining room, as “pure fantasy.”

Akin also received a late boost from former presidential hopeful Newt Gingrich, who sought to rally voters by portraying Akin as the anti-establishment candidate running against the monied interests in his own party as well as the Democrats.