Texas Gov. George W. Bush and Arizona Sen. John McCain continued their argument over tax cuts and Social Security today, with McCain charging that Bush's tax proposal would do nothing to alleviate a "growing gap between rich and poor in America."

McCain's accusation highlighted the growing ideological divide between the Republican Party's two leading presidential candidates, and Bush was quick to counter that his rival sounded more like "Al Gore or Bill Bradley" than a conservative Republican.

"There's a fundamental disagreement with Senator McCain and me," Bush said in a taped interview on CNN's "Late Edition." "He trusts money left in Washington, D.C., will be properly spent. . . . I happen to think it's going to be spent on bigger government and more programs. Appropriators are appropriators and they're very good at it."

The continuing disagreement on the Sunday talk shows, which echoed Saturday's Republican debate in Iowa, demonstrated just how much Bush and McCain have staked their candidacies on the political appeal of their competing plans. With eight days left before the Iowa caucuses and little more than two weeks before a New Hampshire showdown between the two candidates, the tax issue appears likely to dominate the dialogue.

"We think taxes is going to be an important issue in New Hampshire," Karl Rove, Bush's chief strategist, said on ABC's "This Week." "We think it's going to be the issue that's going to decide the election."

McCain's critique of the Bush plan echoed Democratic criticisms of GOP tax policy in recent years, but the Arizona senator deflected a question about whether he was engaging in class warfare with the Texas governor. "I always thought that class warfare was to take away from the rich," McCain said on NBC's "Meet the Press."

Citing the gap between "the haves and the have-nots," however, McCain said his plan does more to help "working middle-class Americans" by offering them a modest tax cut and greater protection of the Social Security program.

Magazine publisher Steve Forbes sought to jump into the tax debate from the right, calling Bush and McCain the "timid twins on tax cuts" and charging on ABC that "neither one gets rid of this horrible tax code that no living human being understands."

Later, campaigning in Iowa, where he hopes to finish a strong second to Bush, Forbes continued to challenge Bush's tax-cutting record in Texas, claiming that many Texans never really felt the property tax cuts approved there in 1997. "I want real tax cuts, not phantom tax cuts," Forbes told reporters in Indianola.

McCain, who was in Phoenix today, reiterated previous criticism that Bush's plan would give roughly 36 percent of the benefits to the wealthiest 1 percent of taxpayers. "Are you going to take the surplus and put it all into tax cuts, or are you going to take some of that surplus and cut middle-income [taxes] and pay down the debt, make Social Security solvent and give some money into Medicare?"

Bush acknowledged that he would cut top rates for the rich but said his plan helps lower-income families more than McCain's does. "It is a substantial tax cut for everybody," he said.

An independent study by Citizens for Tax Justice confirms McCain's claim that Bush's plan gives most to the top 1 percent of taxpayers but also shows that the Bush plan gives more to the lower 60 percent of taxpayers than does the Arizona senator's proposal.

On another issue, Bush and McCain defended their refusal to take a clear stand on whether the Confederate battle flag should be allowed to fly over the South Carolina capitol. On abortion, Bush sidestepped questions about whether he would support all the language in the 1996 Republican platform plank on abortion.

In Waterloo, Democratic candidate Bill Bradley told supporters honoring slain civil rights leader Martin Luther King Jr. that "from my perspective, that flag should come down."

Meanwhile, the three other Republican candidates sought to assure their supporters that they would not be deterred by a poor showing in the Jan. 24 Iowa caucuses. Gary Bauer and Alan Keyes, competing with each other and with Forbes for social and religious conservatives, dismissed questions on "Fox News Sunday" about the consequences of finishing lower than third.

"I've won all the debates, in terms of people's perception," Keyes claimed.

Utah Sen. Orrin G. Hatch, who consistently lags the rest of the field, said a poor finish in Iowa could end his candidacy. "If I can finish in the top four, I'd be doing very well," he said. "If not, we'll have to look at it."

Staff writer Thomas B. Edsall in Waterloo contributed to this report.

CAPTION: Sen. John McCain (Ariz.) speaks at debate of Republican presidential candidates Saturday in Johnston, Iowa. Listening is Texas Gov. George W. Bush.