WASHINGTON - Republicans and Democrats are beating each other up on the issue of terrorism in the wake of the alleged London airplane plot, but polls show that most Americans are far more worried about the war in Iraq.

That"s bad news for President Bush and his Republican allies because, with congressional elections less than 100 days away, most voters don"t think the war was worth it and don"t like Bush"s handling of it. Pollsters say that any boost the president gets from the alleged plot to blow up trans-Atlantic aircraft isn"t likely to alter negative opinions about the war.

"Iraq is far and away the Number 1 issue. Nothing comes even close," pollster John Zogby said. "It"s the elephant in the living room."

Strategists in both parties have gone into overdrive to seek political gain from allegations that terrorists in London were plotting an operation to rival the attacks on Sept. 11, 2001.

Democrats say the developments highlight the nation"s vulnerability under Bush"s leadership. Republicans say the news from London shows that the president"s policies are working.

Voters don"t seem particularly impressed with either argument.

Bush"s job-approval rating has barely budged since last week"s arrests of some two dozen suspected plotters. Three nonpartisan national polls taken after the arrests in London - for CBS, for Newsweek and Zogby - found the president"s job-approval rating in the mid- to upper-30s, unchanged from last month.

Andrew Kohut, the director of the Pew Research Center for the People and the Press, said voters didn"t necessarily count victories in the war on terrorism as relevant to Iraq.

"The indicators there (in Iraq) aren"t terrorist bomb plots. The indicators are casualties and chaos, which people can see on their TV screens," he said. "It is one of the biggest problems for the president. What"s not good for the president is not good for Republicans."

While headlines diverted attention over the past month to Israel"s conflict in Lebanon and then the alleged airliner plot, Iraq accelerated its drift toward all-out civil war.

Escalating sectarian violence pushed the death toll among Iraqi civilians to more than 3,400 in July, an all-time high, according to figures from Iraq"s Health Ministry and the Baghdad morgue, as reported Wednesday by The New York Times. That"s up 9 percent over June and nearly double January"s death toll.

American casualties are down, but the spreading violence pitting Iraqi against Iraqi has virtually eliminated any prospect of U.S. troop withdrawals before November"s congressional elections.

Zogby said the challenge for Democrats was to convince voters that they had a plan to bring the troops home.

"Democrats have got to do better than `We care, too,"" he said. "They"ve got to be able to come up with a credible exit strategy."

Republicans expressed confidence that the renewed focus on terrorism would benefit their party in November. Bush has held a series of events on national security and terrorism since last week"s arrests in the alleged plot, all aimed at driving home the message that he"s working hard to protect Americans.

There was at least a glimmer of good news for the president in recent polls. The Newsweek poll found that 55 of Americans approve of his handling of terrorism, up 11 percentage points from the magazine"s May poll. But his overall approval rating was essentially unchanged at 38 percent.

White House spokesman Tony Snow said Bush"s standing would improve if voters could see more progress in Iraq.

"The American people see headlines, they hear about these appalling acts of violence and they are rightly concerned," he said Wednesday. "What they don"t see are the operations ongoing, the apprehensions of terrorists, the seizure of weapons caches, all of which are going on on a daily basis."