Sen. Warren B. Rudman (R-N.H.), who has become something of a television personality as vice chairman of the Senate select committee on the Iran-contra affair, is being excoriated in his own back yard for his behavior during the investigation.

Leading the attack is Jim Finnegan, who has signed nine anti-Rudman editorials July 9-22 in the Union Leader in Manchester, the conservative, influential New Hampshire daily that supported Rudman's Senate candidacy last year. "Rudman's Treachery," "Rudman's Cheap Shot" and "North Made Him 'Sick' " are sample headlines.

"When we feel strongly about something, we express it in terms you can understand," said editorial page editor Finnegan, who has written editorials for the paper since 1957. "We just think his was an abominable performance."

Meanwhile, publisher Nackey S. Loeb wrote a series of Page 1 editorials in which she answered the question of whether Marine Lt. Col. Oliver L. North is a hero ("YES!") and provided addresses for North and members of the House and Senate investigating committees.

The Union Leader was particularly incensed at Rudman's praise for Senate committee Chairman Daniel K. Inouye (D-Hawaii) and his harsh questioning of witnesses such as North and contra leader Adolfo Calero.

The paper referred to Rudman as Inouye's "principal yes-man."

"Why didn't Rudman speak out in strong protest two months ago when Inouye went to the news media and prejudged the entire question . . . suggesting that {President} Reagan personally approved of illegal conduct?" a July 9 editorial asked.

"No tactic employed to date in the Iran-contra hearings," another said, "has been more contemptible than Rudman's move . . . to cheapen the debate by using Inouye's splendid military record as a rhetorical weapon with which to attack North."

The paper also took aim at Rudman's criticism of North's testimony about his efforts to raise private funds for the contras.

It asked, "Why does he not at the same time reemphasize where he stands . . . on the abominable Boland Amendment that made such fund solicitations absolutely essential to the survival of democratic forces under assault by Soviet Hind helicopters?"

Another editorial attributed Rudman's attitude to "a bad case of Potomac Fever, made worse perhaps by too much exposure to the television klieg lights."

The people back home, it warned, "are more sick of Washington politicians than of anything Colonel North did."

Rudman says he has no quarrel with the paper's criticism.

"The Union Leader is known for its very aggressive editorial policy," he said. "That is no surprise to someone who lives in New Hampshire, and it's no surprise to me."

Rudman noted that he was reelected last year with more than 60 percent of the vote and said the paper's legendary ability to make or break a candidate is limited to hotly contested Republican primaries. "I think that's where they have their greatest influence," he said.

The Union Leader appears poised to use Rudman's Iran-contra performance as ammunition in the Republican presidential primary next year. Last Wednesday, it blasted Senate Minority Leader and presidential candidate Robert J. Dole (R-Kan.) because he recently lauded Rudman's work on the Iran-contra committee.

"We'll take it into account along with everything else," Finnegan said, looking forward to the Union Leader's endorsement in the state's key Republican presidential primary.

Although the paper's circulation is up, Finnegan said new residents -- voters who have moved here to work in the state's high-tech industries -- and new mass media may be diluting the Union Leader's power to sway voters. As Rudman said, "The state has changed enormously."

Loeb plays down the paper's influence in state affairs and said it has never tried to be king-maker. "We've always said what we've felt and let the chips fall where they may," she said.