Washington — It's still ''big brother'' abroad and ''big government'' at home. Martial law in Poland and a new US budget that threatens huge deficits are seen as testing the basic character of the Reagan administration on the brink of its second year.
The Polish crisis is easier for the President to handle politically, because it appears to confirm Mr. Reagan's primary foreign policy tenet, that the Soviet Union is the central ogre in global affairs. The public, by 3 to 1, favors economic and political sanctions over American military action should the Soviets march into Poland, surveys show. So the President is not pressed toward rash action.
''A situation like Poland, tragic as it is, can only help Reagan,'' says Thomas E. Patterson, director of Syracuse University's Maxwell School of Citizenship and Public Affairs. ''There is one idea behind Reagan's foreign policy - that the Soviet Union is our mortal enemy. Poland gives at least face value to this view. It helps him out with protection of his defense spending. As long as the US is not directly involved - which differentiates it from the Iranian crisis - the President can only benefit from it.''
Big government at home is proving no less formidable an opponent for Reagan. Domestically, the President is resisting compromise on the basic conservative principles by which he arrived at the White House.
Yielding too much in the form of tax hikes in the fiscal 1983 budget to offset $100 billion-plus deficits is seen by some Reaganites as giving in too soon to the ''pragmatic,'' ''accommodating'' GOP style of the Ford and Nixon years. Other Republicans appear to advocate a return to a gradualist, moderate, and more compromising economic approach, which annoys the President.
''Reagan thinks everyone around him is acting too quickly,'' says one administration official. ''He really doesn't want any tax increases, beyond the ago to Reagan and got smacked down. Everybody - his staff, Republicans on the Hill - is trying to leave the door open for somebody who doesn't really want it open.''
''I don't think anybody knows what he'll decide,'' says another Reaganite familiar with the Californian's decisionmaking style. ''The preponderance of the people coming to him and making the case for a tax increase may be so persuasive that he might say, grudgingly, 'OK, we'll try it your way.'
''Or he might say, 'No, I'm not Jerry Ford or Richard Nixon or Jimmy Carter. I'm not going to back off.' Personally, I'd like him to stick to his program. This whole economic business is imprecise enough that no person can guarantee anything. We've lived under a pragmatic, accommodating philosophy for years with no great success.
''He understands now and then you have to accommodate, to show yourself reasonable, to work with the Hill. He's the sort of fellow that wants to get along. I hope, if he does that, it'll only be a sop. The public isn't impatient with him yet. He still has time.''
Despite all the fuss in Washington in recent days about Reagan's own advisers and Republican leaders urging him to nearly double his proposed tax increases for next year, the President could yield and still insist that the main lines of his program are in place, and that he has not relented, some advisers argue.
''I think they're more comfortable with what they're doing, more secure and at ease with their progress than the press suggests they should be,'' says Syracuse's Mr. Patterson of reporting that suggests the administration is ''running scared on every front.''
The administration gave itself predictably good grades in its own first-year report, issued by the White House Dec. 22.
On the White House staff side, a top-level review could soon reveal a foursome replacing the troika closest to the President. Assistant Secretary of State William P. Clark is seen as the most logical new White House aide. Mr. Clark had been chief of staff for Reagan during his years as California's governor. His quickly acquired foreign policy expertise could provide the needed backup for policy aide Edwin Meese III and national security adviser Richard V. Allen, on administrative leave. ''Bill Clark could handle any job in the White House,'' affirms one White House staffer.
However, departures by aides like Mr. Allen or Michael Deaver, or the addition of a Clark, would not likely change the policy thrust of the Reagan administration, agree followers who know Reagan well.
Outsiders, too, expect Reagan to hew to his conservative fundamentalism.
''Reagan gives his people free rein, gives them a lot of opportunities,'' Patterson says. ''He's not like Carter, who had to have his finger on every button in the house.
''Reagan has a clear sense of direction: 'You know what I want, and as long as you operate within that framework you'll be fine with me and I'll back you up completely.' Overstep the boundaries, though, and you're in trouble.''
Presidential scholar Thomas E. Cronin sees Reagan's on-trackness less positively. ''A lack of curiosity marks this President and this administration more than any I've seen,'' Mr. Cronin says. The Reagan ''legacy in retrospect will be viewed as simple, unwilling to make distinctions,'' he adds. ''Reagan has no interest in tax equity, only in tax reductions - an important distinction.''
''No president has been evaluated as a great president who has not been concerned with the American people, broadly speaking,'' Cronin says. ''Lincoln did care about black Americans. Franklin Roosevelt did care about a competitive system which allowed consumers to have a break and the average Joe some security.''
Cronin does not expect Reagan to change course. ''This President has some flexibility - as he showed in the (Sandra) O'Connor Supreme Court appointment and in El Salvador - but he's to the right of Jerry Ford and Richard Nixon, that's clear,'' Cronin says. ''He has a simpler mission. If you really know as a true believer what needs to be done, then you've got to plow ahead. He's more in that category than any president we've had in a long time - maybe since Hoover.''