Constructive criticism of any institution is crucial to its success, but that doesn’t seem to apply to the current conflict between University of Hawaii leadership and key members of the state Senate who have considerable influence over its budget.

There’s little sign that anything useful is being constructed here, at a time when collective efforts should be leading improvements to the state’s public university system.

The relationship, which has deteriorated for years, has hit a particular low point in the past two years, with the politicians’ dissatisfaction focused sharply on UH President David Lassner.

Just how low it had sunk became apparent in a Sunday story by Honolulu Star-Advertiser writer Esme Infante that quoted state Sen. Donovan Dela Cruz, the chairman of the Senate Ways and Means Committee, and Sens. Donna Mercado Kim and Michelle Kidani, the respective chair and vice chair of the Senate Higher Education Committee.

In separate interviews, Dela Cruz said Lassner had “run his course” after some 10 years at UH’s helm; Kim said he “is lacking the vision and the confidence of the university as far as moving forward”; and Kidani said she wishes the UH Board of Regents “would start looking for someone else.” But then in an unusual Sunday afternoon statement, the trio disputed the published report, saying that they had not specifically called for Lassner’s resignation, but were merely channeling other critics “who feel that a change in leadership may be necessary.”

The response acknowledged that “the final decision on the leadership and future direction of the university system continues to rest with the Board of Regents.”

That is a critical admission: The regents are the policymaking board for the UH system.

Senate committee leaders, who do help shape the budget enacted for the university, thus should back off their impulse to micromanage policy decisions, the hiring of the president chief among them. This public airing of tensions could damage perceptions about UH among research funding institutions and the general public.

In defending their criticisms, the three senators cited complaints they’ve heard from unnamed students, parents, faculty, former regents and “members of the university community.”

Dela Cruz, Kidani and Kim told the Star-Advertiser about their own specific disagreements as well, over how the UH administration holds faculty accountable for teaching enough classroom hours and on the need for more progress in workforce training programs.

These are legitimate points of inquiry, but the senators’ push for overhaul at the very top is anything but productive. If the aim is to pick up the pace toward achieving their goals, the strategy should be working with UH on clear timelines for achieving them. That’s not the way these Senate panels have conducted themselves for a very long time.

Further, replacing the president can unsettle the institution for months or even years, as Hawaii residents have witnessed in the past. There has to be good reason to justify all the disruption it will cause.

That’s where the senators have failed to make their case against Lassner.

For example: There is no dysfunction between UH and corresponding committees in the House, and all four members of Hawaii’s congressional delegation lined up solidly in support of the president.

The senators also faulted Lassner’s expansion of the Clarence T.C. Ching Athletic Complex to serve UH football when the Aloha Stadium rebuild bogged down. That’s nonsensical. UH was presented with a make-it-work challenge, and Lassner made it work.

There are other metrics weighing in his favor, too, such as encouraging trends in graduation rates and, last year, a record $505 million in research funding.

If Hawaii is to continue on an upward trajectory for its public university, state leaders are all going to have to work in tandem toward that end.