Vice President Bush offered a preview today of President Reagan's Hispanic strategy with a feisty political attack in which he accused Democrats of taking Hispanic voters for granted.

In a luncheon speech to the National Hispanic Voter Registration Conference here, Bush said Hispanics "living in the barrios are often told, 'pull the big lever, vote it straight' " for Democrats.

But Bush said Democrats sought Hispanic support "to get power for themselves. What happened to the people? Nothing much at all. And look at one-party domination if you want to find people that are taken for granted.

"Look in one-party states if you want to find discrimination in voting or redistricting," he added without further elaboration.

Bush said that he and Reagan are "not writing off any American in terms of 1984" in an expected reelection campaign.

Sen. Edward M. Kennedy (D-Mass.) followed Bush, who gave a detailed defense of the administration record on the economy and on civil rights. Kennedy charged that Reagan's "is the most anti-Hispanic administration in modern history . . . . We are told that we have just rounded the corner of prosperity, but there is no prosperity for the 12.3 percent of Hispanic workers who are out of work."

Bush and Kennedy came to this conference--devoted to the registration of 1 million new Hispanic voters--as part of the early but increasingly intense jockeying over the Hispanic voting block.

Reagan has performed better among Hispanics than other Republican candidates, but Democrats are looking to high unemployment as an issue that will propel Hispanic voters back into their traditional place in the party.

The White House, meanwhile, is planning a series of speeches and events to underscore Reagan's commitment to values and concerns shared by Hispanics. In particular, administration officials say they believe Reagan will need to do well among Hispanics in 1984 as a buffer to the expected large turnout among black voters for the Democratic nominee.

In outlining Reagan's approach today, Bush came prepared with a detailed list designed to demonstrate what the administration has done for Hispanics.

To loud applause he said that he and Reagan "remain firmly committed to bilingual education . . . we are pledged to this end."

Bush recalled the high inflation and slow growth period of the Carter presidency and insisted that the administration's efforts to bring about recovery with low inflation have been a benefit to Hispanics. However, there was only scattered applause when Bush said, "There are now more people employed in this country than ever before in history."

Bush said that the administration "signed into law the longest extension of the Voting Rights Act in history." He didn't acknowledge that the administration had dragged its feet on renewal of the voting rights law.

Bush also listed what he said was the administration's commitment to increasing minority businesses and quality education and cracking down on drug abuse.

"It's this administration that shares the Hispanic values of family, neighborhood, church, freedom and opportunity," he said in repeating a line from Reagan's 1980 campaign rhetoric.

While Bush was critical today of the record of former president Jimmy Carter and former vice president Walter F. Mondale, who is now seeking the Democratic nomination, he appeared to shy away from a more direct attack on Mondale. Twice Bush dropped references in the text to the "Carter-Mondale administration" and substituted "our predecessors."