JOHNSTOWN, Pa. — After a week of increasingly nasty rallies in which John McCain and Sarah Palin hammered Democratic rival Barack Obama over his "association" with a 1960s-era radical, the Republican candidates changed tactics yesterday during campaign swings through two presidential battleground states. Palin launched a new front in the culture wars here, attacking Obama on abortion, and in Iowa, McCain concentrated on a critique of Obama's spending proposals. Emotions — particularly anger — have been running high at Republican gatherings. During a town hall Friday in Minnesota, a woman referred to Obama as an "Arab," leading McCain to correct the misperception and defend his opponent as a "decent ... family man."

Palin yesterday seemed to acknowledge the nastiness. After chastising Obama for his "unconditional support for unlimited abortions" she told a rally in this heavily Catholic, socially conservative Democratic stronghold that "Americans need to see his record for what it is. And please, it is not negative, it is not mean-spirited to talk to about his record."

When Obama was an Illinois state senator, she said, he opposed proposals to outlaw what critics refer to as "partial-birth abortion." She invoked two Catholic Democrats who opposed abortion — the late New York Sen. Daniel Patrick Moynihan and the late Pennsylvania Gov. Robert Casey — in an attempt to characterize Obama's views as extreme.

Moynihan, Palin said, "described partial-birth abortion as 'too close to infanticide.' Senator Obama thinks it's a constitutional right, but he is wrong."

Obama senior adviser Anita Dunn said Palin's comments "show that with this election, the right to choose hangs in the balance."

Meanwhile in Iowa, McCain advocated for his tax cuts and his plan to balance the budget by "the end of my term in office." He offered a scathing critique of the price tag of Obama's spending proposals and him of being vague.

"We've all heard what he's said, but it's less clear what he's done or what he will do," McCain told a crowd of more than 1,000 gathered in Davenport. "Rather than answer his critics, Senator Obama will try to distract. ... He has even questioned my truthfulness — and let me reply in the plainest terms I know: I don't need lessons about telling the truth to the American people. And were I ever to need any improvement in that regard, I probably wouldn't seek advice from a Chicago politician," McCain said.