House Majority Leader Jim Wright (D-Tex.) asserted yesterday that a conservative group has targeted him and two other House leaders for defeat 18 months before the 1982 election to intimidate Congress into passing the Kemp-Roth tax cuts, which would greatly benefit the group's wealthy backers.

Terry Dolan, chairman of the National Conservative Political Action Committee (NCPAC), called a news conference Monday to announce that his group, which until now had concentrated on defeating liberal senators, has added to its list of 1982 targets Wright, House Budget Committee Chairman James R. Jones (D-Okla.) and Ways and Means Committee Chairman Dan Rostenkowski (D-Ill.).

Dolan called them the three "most obstructionist" members of the House standing in the way of President Reagan's economic program. NCPAC plans to spend $1 million trying to defeat these three leading House members and Sen. Paul Sarbanes (D-Md.), $450,000 of it against Wright in his Fort Worth district.

Wright responded yesterday with a statement that it was obvious NCPAC is not merely interested in promoting conservatism because Jones is a conservative who beat out a liberal for the budget chairmanship and Rostenkowski is well known as a middle-roader.

The obvious motive, said Wright, is that NCPAC's "wealthy clients have a vested interest" in promoting the Kemp-Roth tax bill adopted by Reagan of 10 percent tax rate cuts a year for three years, and NCPAC "has decided to browbeat and punish" the three House members "because we are standing in the way of the unfair and inflationary" Kemp-Roth bill.

Jones has fashioned a budget resolution that cuts spending deeper than Reagan had proposed and omits Kemp-Roth. Rostenkowski has prepared his own one-year tax cut bill, and Wright has been working with both of them.

Wright said Kemp-Roth would "confer enormous benefits upon the extremely rich and do little or nothing for" middle- and lower-income families. Kemp-Roth would give a family with a $20,000 income only $400 black the first year but a $200,000 family would get $7,000, Wright said. $4