Gov. Michael S. Dukakis swept to commanding primary victories in Ohio and Indiana yesterday as he rolled past the Rev. Jesse L. Jackson toward the Democratic presidential nomination. Vice President George Bush, uncontested as usual, celebrated his certain Republican nomination at a rally a few blocks from the White House.

Jackson won the District of Columbia, capturing a Democratic consolation prize and his first primary victory in six weeks. But Dukakis shed some of his customary caution and proclaimed, "I think it's going to be difficult" for his only remaining Democratic rival to deny him the nomination.

Countered Jackson: "We're moving right along."

The vote count showed otherwise, and Dukakis was adding almost 200 delegates to his total. "We still have 500 some odd [delegates] to go," he said.

Dukakis fashioned side-by-side landslides in Ohio and Indiana, routing Jackson by margins of greater than two-to-one. He also padded his substantial lead in national convention delegates and ratified his status as faraway favorite to win the Democratic nomination and meet Bush in the fall campaign.

The delegate tabulations were slower than the popular vote, but Dukakis led for 175 delegates from the three contests to 70 for Jackson.

The day's Democratic delegate arithmetic clearly favored Dukakis, the prohibitive favorite to lock up thenomination weeks before the Democratic NationalConvention convenes in July in Atlanta. Ohiopicked 159 delegates to the Democratic NationalConvention, Indiana 79 and the District ofColumbia 16.

"I feel great about today," the Bay Stategovernor said at a news conference in Boston.

Bush said he felt great, too, as he addressed acheering group of supporters at a rally staged tocelebrate last week's clinching of the Republicannomination.

"It all boiled down to working together," saidthe vice president, who exiled the GOP oppositionwith a 16-state primary sweep on March 8.

"And yet, "Bush told his supporters, "I don'tfeel any finality to what has happened now at all.We've passed the first step, a tremendouslyimportant step... But now we've got a long way togo."

Network interviews with voters at the pollingplace indicated that Jackson won his customaryoverwhelming support among Black voters. TheCBS-New York Times poll said Jackson won onlyabout 15 percent of the white vote in Ohio andabout 10 percent in Indiana.

ABC said its poll indicated that about 60percent of Jackson's supporters in both statessaid they would vote for Dukakis over Bush in thefall campaign, with only 6 percent saying theyfavored the vice president.

Dukakis' twin victories were hailed by someDemocratic Party leaders who are hoping to reclaimthe White House after eight years of Republicanrule.

"It may be boring but I love it," DemocraticNational Committee Vice Chairman Lynn Cutler saidas she surveyed a race that has gone fromturbulent to utterly predictable over the pastmonth with a string of Dukakis primary victoriesin Connecticut, Wisconsin, New York andPennsylvania.