Chicago's Mayor Richard Daley has bitterly declared that he will brook no trouble from would-be demonstrators when the Democratic Convention gets underway in August. "I think the great mass of American people has had enough of those who carry Viet Cong flags in the streets of this country, and are getting fed up with the cry of police brutality," he told his wildly applauding City Council.

"No one is going to take over the city," stormed Daley. "They won't take over the convention or any street. If it is necessary to put on 5,000 more policemen, I'll ask for authority." He may have to.

Dissident Democrats and other angry opponents of the war, of course, have been talking of marching on the barn-like International Amphitheater much as they marched on the Pentagon last October. The prospect already has police mapping contingency plans.

From a policeman's point of view, the situation could hardly be worse. The decaying Amphitheater will be hard enough for delegates to get to without the harrassment of demonstrators. If protestors want to make things uncomfortable, the police will be hard pressed to stop them.

There are no hotels and few places to eat in the area, and delegates will have to commute from the Loop via a single expressway or the back streets of the ghetto. The city's mammoth lakefront exhibition hall--closer to downtown, isolated from residential ears, and far easier to defend--was gutted by fire a year ago, but Daley's clout and assurance of peace brought the party to Chicago anyway.

If there are demonstrations outside the hall, the neighbors are not going to like it. Though the Amphitheater is ringed by the bleak slums of the South Side ghetto, the immediate area is heavily white and largely Irish. Daley himself lives not too far away. Should Negroes march in, things could get ugly. Civil rights demonstrators have marched on the mayor's house many times, and they have, on occasion, been met with bricks and bottles.

Negroes' reaction to the convention is at this point far from certain. Chicago could be in for a massive explosion. There is, in at least one store window less than a mile from the convention hall, a dusty sign reading "Soul Brother," left over from a previous flare-up. Even the chill of winter has not been enough to discourage Negro youths from a recent rampage through a South Side neighborhood.

Events are now shaping up that could very much intensify an explosion, inflaming Negroes and spurring them to action. But these same developments could, if the Democrats are shrewd enough, divide the dissidents and put them at odds with a large segment of Chicago's Negro community.

The key is Mississippi. Negroes from the Magnolia State are going to flock to Chicago this summer in a replay of the 1964 Atlantic City attempt to unseat the party regulars. That year the party handed Negroes a compromise, seating of two of the challengers as guests; this time, a compromise will be more difficult.

There is, above all, a massive wellspring of sympathy in Chicago's ghetto for Mississippi civil rights activity. Most of the city's nearly one million Negroes have roots in Mississippi. "Chicago, Chicago, that's all you ever hear around here," says an ex-plantation worker in Greenville, Miss. Negroes in the Delta speak not of going North but of going to Chicago; and for Negroes in Chicago, going home means a visit to Mississippi.

If the Negroes challengers from Mississippi are forced to sit outside the convention hall as they were in Atlantic City, they are sure to be joined by throngs of irate supporters and by every black power firebrand in town.

But if this year's challenge is potentially more explosive, it is not nearly as simple as 1964's. In fact, the political complexities may pose as much of a problem for the anti-Johnson forces as for Johnson himself.

Delegations from two states--Mississippi and Alabama--are likely to be challenged. Party regulars in both states should have little difficulty in complying with the broad civil rights guidelines set down by the Democratic National Committee. The guides say only that party elections--as for county convention delegates--must be open to Negroes; they do not say that the national convention delegations must actually be integrated.

Even in Mississippi, with 42 per cent of the population Negro and a dozen counties capable of electing Negro officials, fair elections would not necessarily result in any Negroes on the delegation. It is selected by a statewide convention whose delegates are in turn chosen at the county level. Negroes could not possibly gain a majority of the state's 82 counties.

But neither Alabama's nor Mississippi's delegation is likely to submit to one national party dictum--a pledge to support the party's nominee. In Alabama, Johnson supporters have had to charter a new party in order to assure that the President's name--they have no doubt he will be re-nominated--will be on the ballot. The regular party will support former Gov. George Wallace.