Both races were marked by accusatory campaign commercials on a scope that was unprecedented for a presidential campaign. Dukakis aired a commercial featuring an acrobat doing somersaults as he tried to depict Gephardt as a man who flip-flops on the issues. Dole ran commercials saying Bush had approved arms-for-hostages swaps during the Iran-Contra affair. Thus ended what amounted to a Southern regional primary campaign, an idea hatched by Democratic officials who wanted to give a moderate-to-conservative contender a boost toward the party's 1988 nomination. The idea was to help nominate a Democrat who could run strongly across the South in the general election campaign in the fall _ and bolster the prospects of Democratic candidates in local elections. But whatever the theory, the result was a struggle carried out largely through costly television commercials with no particular Southern cast. The candidates, trying to campaign in an impossible number of areas simultaneously, often were reduced to staging appearances at airports so they could leave as quickly as possible for the next stop. But the commercials were eye-catching, particularly on the Democratic side. Voters who didn't see the ads would read about them in the paper or see clips on the television news. Gephardt attacked Dukakis for raising taxes while governor of Massachusetts and mocked Dukakis for once suggesting that farmers diversify their crops by growing Belgian endive. He also aired a spot seeking to portray Dukakis' campaign as guilty of a string of dirty tricks. Dukakis returned fire with ads featuring an acrobat doing somersaults, while the announcer attacked Gephardt as flipflopping on critical issues. Gore retooled his message in mid-campaign with a populist appeal designed to siphon off some of Gephardt's support. His final flurry of ads attacked Gephardt and Dukakis. In one commercial he even added a mild jab at Jackson. As much as anything, Super Tuesday was a test of Gore's Southern strategy for gaining the nomination. Alone among the contenders, he ignored the Iowa caucuses and spent months collecting endorsements and campaigning in his native region in hopes of jump-starting his campaign at home after others had left the field. However, among the original Democratic candidates, only Bruce Babbitt was gone by Super Tuesday. The Democratic idea for a regional primary suited the Bush forces fine. The vice president's aides quickly spread the word that they had erected a ``Southern fire wall'' that would contain any damage resulting from defeats in earlier contests. And when Bush finished a poor third in the Feb 8 Iowa caucuses, it looked like the theory would get a test. But then came Bush's victory in New Hampshire's primary, followed by his convincing triumph in the South Carolina primary on Saturday. And instead of merely hoping to hold his own, the vice president spent the last two days campaigning and advertising heavily in Dole's strongest state in Missouri in hopes of pulling off a sweep. Dole suffered through a difficult period as his campaign manager fired two senior aides in an internal struggle for control. Even as the polls opened on Super Tuesday, the contenders were looking ahead to the next round in the nominating wars. Dole had begun airing television commercials in Illinois, a contest his aides said he had to win to sustain his candidacy.