The grudging truce arranged here between Democratic governors and President Carter may be temporary, but it signifies a departure from blood-letting of the past 19 months and a new consensus among the governors that there are more rewards in loving than leaving the White House.

This strictly-for-business national governors' conference, stripped of the frills and social diversions of the past, suffered from collective fear of a breakdown in the political process that threatens all institutions of government, most particularly the presidency. As Gov. Edmund G. Brown of California told us: "There is a feeling here" that the presidency is becoming an impossible job.

That fear underlines the shift by the Democratic governors away from open season on Jimmy Carter toward a more benign mood of toleration. Whether the new mood lasts will depend on the president's response, and some of the evidence here is that Carter has gotten the message.

A case in point was the White House reversal of a tentative decision to gut the federal-state Regional Development Commissions so dear to the hearts of the governors. The plan, first outlined three weeks ago to 12 Western governors in Vail, Colo., by low-level administration aides, would have centralized authority over those commissions in Washington, drastically reduced the power of the governors and choked off budgetary support.

Angry Western governors led by Montana's Thomas L. Judge were prepared for a counterattack against the White House that would have spilled political blood here. But top-level White House aides, headed by Anne Wexler and Jack Watson, persuaded Carter to retreat and announced the decision on Monday.

There never has been much love between the Democratic governors ad their former colleague from Plains, Ga. Not a single Democrat among the 17 who were elected for the first time in 1970 along with Jimmy Carter supported his pre-convention bid for president. They perceived him as distant, selfish and a loner, never one of them. Most of the 38 present Democratic governors feel the same way today, but their need for Oval Office support in coping with what Brown calls the "tidal wave" of the taxpayers' revolt and the awesome new veto power of special-interest groups makes union with the White House indispensable.

In addition, there was the first faint murmur of something like sympathy for the troubled presidency of Jimmy Carter and the man himself. Gov. Joseph P. Teasdale of Missouri called it "the swing of the pendulum."

"We have begun to rally around Carter," he told us. "Whether you call it sympathy, there is an important mutual interest we have with the president - preventing the dangerous failure of government in this nation."

But so low has the estate of the president fallen that the single act of recording formal support for him by the Democratic governors here was an acute embarrassment. The resolution of support was spontateously popped out by West Virginia's Gov. Jay Rockefeller at a closed-door breakfast during which National Democratic Chairman John White appealed to the governors to back Carter and take command of their state political parties for the 1980 presidential campaign.

When Rockefeller offered his pro-Carter resolution, New Jersey Gov. Brendan Byrne said out loud what many others were thinking: Finding it necessary to go on record supporting a new president only 19 months in office is leading from weakness and reminding the country how low he has sunk.

Once offered, the resolution could not be withdrawn without even greater embarrassment to Carter. It was unanimously adopted.

Rockefeller's resolution is no promise of better times for Jimmy Carter. There was not a solitary Democratic governor here willing to tie his own future to the president's star, and few who did not recount their own horror stories of White House snubs and stupidities in which the governors have sometimes been treated lower than sewer inspectors.

That period may be ending. More important is the underlying fear of whether government can be made to work. The governors know that without an alliance of necessity with Carter the answer must be no, and that prospect fills them with genuine terror.

Broadcasting executive Frank Shakespeare has informed us he has no intention of heading or of serving on Rep. Jack Kemp's new political action committee. Shakespeare said he recently turned down such a role proposed by a Kemp agent as being inconsistent with his business duties at RKO General. Kemp had flatly informed us that ex-Nixon aide Shakespeare would run the committee.