Viewed from this sun-drenched state capital, where Ronald Reagan first made his mark on government, the prospects of the Reagan presidency do not look inspiring.

It took Republican Gov. George Deukmejian, a state legislator during Reagan's eight years as governor, nearly two months to endorse the president's ballyhooed tax-overhaul plan. When it finally came, Deukmejian's endorsement was so hedged with concern for what the tax plan would do to California's agricultural and timber industries that it may have given opponents of the tax plan more comfort than supporters.

But the real concern in California, as elsewhere, is not Reagan's tax proposal but his seeming obliviousness to the consequences of an ever-growing federal deficit. In a state that usually votes Republican at the top of the ticket and Democratic below it, some GOP consultants are worried that Reagan's sanguine rejection of a needed tax increase to reduce the deficit may spell trouble for Republican candidates just at the time their party seems to be moving into a parity position with the Democrats.

Because the president, as usual, is considerably more popular than his policies, some Reagan-watchers here are blaming White House chief of staff Donald T. Regan for the administration's intransigence. Regan, largely unknown in California, burst into public consciousness in Sacramento with an over done in-charge role while the president was recuperating from last month's cancer operation.

One Sacramento lobbyist close to Reagan's gubernatorial administration deplored chief of staff Regan's feuding with Republican senators and said it looked to him as if the president had "a first-term staff in his second term." His point was that Reagan started out in California with a strong-man chief of staff. When that didn't work, he turned to a Cabinet-style staff system that infused his administration with a broad range of ideas and strategies.

It was this more open staff system that made Reagan aware of the potential of cooperating with the Democrats to obtain the welfare system overhaul and tax and education measures that became the hallmarks of his second-term achievement as governor in California. While the cast of characters partially changed, the same sort of system prevailed during his first term in the White House, also a period of legislative success.

One achievement of the staff system in California -- after then-state finance director Caspar W. Weinberger departed to serve in the Nixon administration -- was passage of legislation allowing state income tax withholding. Reagan had said he was "in concrete" in opposing this proposal, which he correctly predicted would make it easier to raise state taxes. When he gave in, he told reporters that the sound they heard was "the concrete cracking around my feet."

Regan, a proven manager, does not seem to be interested in busting up the concrete surrounding the president's opposition to new taxes. The chief of staff does not seem to recognize that power is shared in Washington and that no president, not even Reagan, can ultimately prevail by brushing away the concerns of his party's leadership.

While it may be convenient and even appropriate to blame Regan for the administration's present difficulties, history is likely to take an unkind view of a president who chooses to deal with an issue by ignoring it.

In California, the balanced-budget requirement that Reagan is now trying to impose on the federal government forces any governor to deal realistically with the need for taxes. In Washington, presidents must on their own summon the wisdom to set aside their prejudices and campaign rhetoric and look ahead at the economic landscape they will leave to their successors.

Reagan once realized that nations, like individuals, cannot forever run an unbalanced budget without paying the consequences. Back here where it all began, there is increasing uneasiness that the president, despite his sterling personal qualities, is now unwilling to face economic reality.

Reaganism of the Week: Promising a meeting of his top appointees that he will oppose tax increases, the president said: "I've been sleeping with a veto pen in my pajamas."