Top foe of Chicago's mayor switches parties. Republicans hope Democrat's defection will attract white voters

In other cities, it would be a shocking political move. In Chicago, it's been expected for months. Edward Vrdolyak, once Chicago's second-most powerful Democrat, is now a Republican. ``I want to be part of a party that has brought America back,'' he told supporters Tuesday night at a Serbian Orthodox church here.

The switch is the latest sign of the ongoing adjustment in Chicago's political structure as the city's first black mayor consolidates his power.

``This place is just terrible,'' says Paul Green of Governors State University in suburban Chicago. ``The good guys and the bad guys keep changing uniforms.''

For Mr. Vrdolyak, the former county Democratic chairman and city alderman, the party switch is expected to boost his prospects for higher political office. For the Republicans, the move sparks new hope that the party can revitalize its moribund structure.

``I think Vrdolyak's the type of person that can help the party,'' says Aldo DeAngelis, a Republican state senator from the Chicago area. ``I think he can help our fund-raisers immensely.''

Cook County party chairman Donald Totten adds, ``It's got to be good for us.''

The Republicans hope that the move by Vrdolyak will spark white ethnic voters and other dissatisfied Democrats to switch over as well. Many white Democratic officials blame Harold Washington, the city's first black mayor, for not reaching out to the white community.

On the same night that Vrdolyak announced his switch, his brother, 10th-ward Alderman Victor Vrdolyak, also said he was becoming a Republican. At least five other elected Democrats are considering becoming Republicans, says Cook County Sheriff James O'Grady. Sheriff O'Grady himself is one of a handful of Democrats-turned-Republican. This spring he defeated the incumbent Democratic - the first time a Republican had won countywide office here since 1976.

But it is not at all clear that either the O'Grady victory or the Vrdolyak means that Democrats will start voting Republican, political observers say.

``I'm not sure anyone can evaluate what's going to happen,'' says Al Ronan, a Democratic state representative. But ``I just don't see real movement among a lot of people'' toward the Republicans.

In sharp contrast to the Vrdolyak switch, other Democrats who have opposed Mayor Washington show no inclination to leave the party. Former Mayor Jane Byrne, who opposed Washington unsuccessfully in the last two Democratic primaries, is now running as a Democrat for county clerk, saying she needs a win. Richard Daley, who opposed Washington in the Democratic primary, plans to run as a Democrat for a third term as Cook County state's attorney. In fact, Vrdolyak appears interested in challenging Mr. Daley for the office.

Even many Republicans aren't sure that Vrydolyak, by himself, will be that big a plus. Some local GOP leaders worry that Vrdolyak will commandeer the local party machinery and are urging him not to run in the 1988 elections.

``I think a lot of Republican leaders, like Totten, fear that Vrdolyak will take over,'' says Thomas Roeser, a Republican and president of the City Club of Chicago.

If Vrdolyak does take over the party machinery, it would not be his first time. In 1983, the alderman of the 10th ward engineered a spectacular coup in the City Council. He forged a dissident majority of aldermen, known as the ``Vrdolyak 29,'' which successfully blunted many of the new mayor's initiatives. Vrdolyak also took over chairmanship of the county Democratic Party - the second most powerful Democratic post after the mayor.

Many black voters branded Vrdolyak a racist for his tactics and stalwart opposition to the mayor. In the next aldermanic elections, Vrdolyak lost his absolute majority in the council and then was defeated earlier this year in his third-party bid for mayor.

Running as a Republican in a county race would circumvent Vrdolyak's problems with black voters in a Democratic primary. In the county, blacks make up only about 26 percent of the vote in a general election, compared to 44 percent in the city.