CRISIS IN THE PERSIAN GULF : Protests Echo Vietnam War Opposition : Politics: Small groups heckle Bush in the Midwest, challenging the U.S. troop deployment.

Like a faint echo of the Vietnam War protests two decades ago, small knots of demonstrators challenging the deployment of U.S. troops to the Persian Gulf are greeting President Bush during his political travels in the American heartland.

They are, to be sure, counted in the twos and threes--perhaps tens and twenties some days--but a far cry from the massive crowds in the late 1960s and early 1970s that shouted their opposition to the Vietnam War and helped bring down the Lyndon B. Johnson Administration in 1968.

Nevertheless, when Bush traveled to Denver, Minneapolis and Omaha recently, there were demonstrators on street corners with insistent signs as his motorcade drove past.

And on Tuesday, for the first time since about 200,000 U.S. troops began arriving in the Persian Gulf after the Iraqi invasion of Kuwait on Aug. 2, Bush’s speeches were interrupted by shouted protests. He was heckled as he spoke to Republican audiences in Des Moines, here at the College of DuPage, 40 miles west of Chicago, and in the evening in Grand Rapids, Mich.

The disruptions occurred as numerous community-based peace groups around the country called for a nationwide demonstration Saturday against Operation Desert Shield, the military code name for the Middle East operation.

For weeks, many of these groups have been circulating petitions and holding teach-ins and vigils in fairly low-key drives. Among them is the Washington Peace Center, which has been picketing the White House every Saturday since late August.

Spokespersons for various coalitions of peace groups said they hope the Saturday demonstrations will elevate the visibility of those who oppose the deployment of U.S. troops in the gulf.

The military operation appears to continue to hold widespread, if decreasing, support across the country, as measured in public opinion polls. But the rating given Bush’s job performance, which jumped immediately after the troops were dispatched, has fallen in recent days--under assault not only from the unresolved crisis but also from the impasse between the White House and Congress over the federal budget and nagging doubts about the state of the nation’s economy.

The drop in Bush’s popularity has been measured in a number of polls, including a poll taken for Times Mirror Co., parent company of The Times; The New York Times/CBS News poll, and the Washington Post/ABC News poll.

The most recent survey--the Post/ABC poll--found that 60% of those questioned support keeping the U.S. forces in the gulf until Iraq withdraws its army from Kuwait, a drop from 75% five weeks ago.

In addition, it found that overall support for Bush’s handling of the crisis has fallen from 78% in September to 64%, and that for the first time a majority of those polled do not think the economic embargo that is the heart of the Administration’s response will succeed in pressuring Iraq to pull out.

Although Bush has insisted that he pays little attention to the polls, he is a careful politician who is said to actively consult his own pollster. And, as he aggressively campaigns across the country for Republican candidates in the Nov. 6 congressional and gubernatorial elections, the White House is closely monitoring such political trends.

The figures in the public opinion surveys measure broad sentiment. On a less scientific but more pointed level were the incidents Tuesday.

Moments after Bush began speaking at a Republican Party fund-raiser in Des Moines, three young men stood up in the middle of the audience, calling out: “Mr. President, bring our troops home from Saudi Arabia! No blood for oil!”

Almost immediately, the Republicans in the audience rose to their feet, waving signs supporting the reelection campaign of Gov. Terry E. Branstad.

As the three men were hustled out of the Des Moines Civic Center, Bush ad-libbed, with an edge to his voice as it rose in pitch and volume to add emphasis:

“You know, some people never get the word. The fight isn’t about oil. The fight is about naked aggression that (we) will not stand.”

Later, he returned to the topic:

“If we don’t stand up against aggression around the world when it’s naked and brutal, who will? The United States has the responsibility to lead and to put together this coalition that says to (Iraqi President) Saddam Hussein very simply, ‘You cannot bully your neighbor,’ ” Bush said.

As Bush arrived at the Civic Center in Glen Ellyn, fewer than two dozen protesters sent up a chant outside, where the air was filled with the foul aroma from a meatpacking plant nearby: “One-two-three-four, we don’t want your oil war.”

Inside, the President spoke in front of a large American flag, and many in the audience waved small flags.

Bush was also heckled during his last stop for the day, in Grand Rapids, Mich., where he was stumping for Republican gubernatorial candidate John Engler and GOP Senate challenger Bill Schuette.

Staff writer Edwin Chen in Washington contributed to this report.