No one can say the honeymoon is over for metropolitan Baltimore's four new county executives. There wasn't one.

The four executives -- two of them political newcomers who scored Election Night upsets -- may have popped a champagne cork or two when the last votes were counted in November. But the party soon ended.

The first 100 days in public office have brought headaches and hard times.

The economic upturn everyone hoped would follow the troops home from the Persian Gulf has yet to occur. Income from taxes and other revenue has dwindled, leaving county governments in a financial crisis. In Baltimore and Anne Arundel counties, the anti-tax sentiment that burned so hotly during the election still simmers. Layoffs and cuts in service are virtually inevitable in deficit-ridden Howard County and a threat in the other three counties.

How have the freshman executives fared in the face of such troubles?

The answer varies from county to county according to two key factors: economic severity and political experience.

Anne Arundel is in relatively sound financial shape, and Republican County Executive Robert R. Neall -- a former state legislator and state drug czar who narrowly lost a 1986 race for U.S. Congress -- knows his way around the political arena. So far he has virtually escaped criticism and had his way.

At the other end of the spectrum, Howard County Executive Charles I. Ecker has no political experience and faces a $31 million deficit, the worse economic situation in the Baltimore metropolitan area. Mr. Ecker, whose affable nature helped him win the election, has angered and upset so many people that some Howard leaders are wondering if his effectiveness has been permanently diminished.

Mr. Ecker and Baltimore County Executive Roger B. Hayden, both Republicans, were swept into office on the same tide of anti-incumbent sentiment. Mr. Ecker defeated Elizabeth Bobo on the strength of his nice-guy personality and his preaching of fiscal conservatism; Mr. Hayden upset Dennis F. Rasmussen by attacking the former executive's perceived image as an inaccessible spendthrift.

A candidate who wins because someone else loses cannot help but face extraordinary pressure once he takes office. During an election, he basically surrenders the spotlight to the person he is trying to defeat. Afterward, the public and press focus solely on him, and people often discover that they don't know their new leader at all. Everything he does becomes subject to intense scrutiny.

Mr. Hayden, a former school board president, seems to have come through this difficult period fairly well.

"He's had a very smooth transition for one who has never been in politics before," said Douglas B. Riley, Republican chairman of the Baltimore County Council.

The fact that Baltimore County still is fiscally sound hasn't hurt. Though Mr. Hayden has promised to hold the line on wasteful spending, he hasn't had to take anything away from constituents and employees, as Mr. Ecker apparently must.

The only executive who has not mandated either a no-growth budget or budget cuts, Mr. Hayden biggest challenge is balancing the needs of the school system's 4,000 new students next year with the cries of tax rebels who feel schools get enough. Mr. Hayden's first budget, due April 16, will provide the first clue as to how well he will fare.

In the meantime, Mr. Hayden clearly has succeeded at the business side of job. Critics say he has eliminated millions of dollars of wasteful spending and appointed qualified people to key positions -- though he offended the County Council when he tried to hire his new administrative officer at a higher salary than the person who held the job before.

He's helped his image by staging all-day sessions where citizens can meet with him personally. And he's dealt well with potentially antagonistic groups, such as county unions now negotiating for raises.

"He said he was going to run Baltimore County like a business, and that's exactly what he's done," Mr. Riley said.

"He is de-politicizing" the office of county executive, said Donald E. Pearce, a former school board member who worked with Mr. Hayden.

But county executives are politicians, and the best ones know the art of operating in the political realm without being controlled by it. Except for Mr. Neall, none of the three new executives seems to have mastered that art.

Mr. Neall "is a real politician; he knows how to treat people," said Anne Arundel Councilwoman Virginia P. Clagett, a Democrat.

Mr. Ecker, on the other hand, has alienated teachers by trying to cut school spending and roll back their 6 percent pay raise. He's sent morale plummeting among county employees by calling for up to 200 layoffs, threatening furloughs and eliminating all raises. He's angered civic leaders by lifting a growth moratorium and attempting to appoint a developer as county administrator. And he faces partisan disputes with Democratic majority on the County Council.

Joyce Terhes, chairman of the Maryland Republican Party, points out that Howard's economic and growth crises guarantee Mr. Ecker will make some people angry, no matter what he does. "No one likes to look at freezing salaries, laying off people or raising taxes, but when you walk into a situation that was not your making, it calls for leadership and having to make tough decisions," she said.

But Mr. Ecker's critics are concerned because they say he doesn't seem to know what tough decisions to make. "He's struggling," said Democratic Councilwoman Shane Pendergrass. "I don't think he knows what he's going to do. We have no idea what he's trying to do."

Mr. Ecker remains unfazed. He says he's concerned neither with the wisdom of what he's done so far, nor the criticism, nor his political future. "I really don't care," he said, asked if there is any way he can politically survive the current mess. "My number one concern is Howard County, not Chuck Ecker. I am worried about the next generation, not the next election."

Mr. Ecker denies he's in over his head. But others are less certain. Two weeks before his budget was to be released April 16, the executive said he was still "considering different options" for solving the budget crisis. "A lot depends on what happens with the state money. It's all still up in the air."

Despite her political experience, Harford County Executive Eileen M. Rehrmann's first 100 days have been nearly as fractious as Mr. Ecker's.

Ms. Rehrmann, the only Democratic executive in the region, served eight years in the House of Delegates, where she enjoyed a close relationship with Gov. William Donald Schaefer. She wanted a strong electoral mandate in last November's election, but defeated Republican underdog Geoffrey Close, whom she outspent 4 to 1, by a mere 700 votes.

Some suspect she is having problems now because her experience as a state legislator has not prepared her for the role of executive.

Early on, Ms. Rehrmann made some major mistakes.

She offered the job of economic development director to a friend whose skills and background were questionable at best and whose resume was padded with exaggerations and half-truths. She froze hiring and warned government employees not to expect raises, then hired her campaign manager as a public relations adviser for up to $25,000 a year.

Ms. Rehrmann also displayed a lack of understanding of county budget processes. In her inaugural address, she enraged former County Executive Habern W. Freeman, now a state senator and arguably the county's most popular politician, when she accused him of "pilfering" an $18 million surplus.

Harford ended budget year 1990 with an $18 million surplus, which Ms. Rehrmann expected to spend when she took office. She didn't understand that money was rolled into this year's budget and was not hers to use.

Ms. Rehrmann showed a better of grasp of financial matters when her first budget was released last week. A no-frills plan that would spend nearly 4 percent less than this year, the budget strikes a delicate balance between sinking revenues and demands for services. It includes no money for raises for teachers or other government workers, a fact that seems certain to generate some discontent.

Some Harford leaders already are unhappy with Ms. Rehrmann's style. "She's kicked about everybody she can kick," said one high-ranking official.

Another complained that Ms. Rehrmann holds vendettas against those who do not do things her way. "You either go along or you don't get along," that official said.

In Anne Arundel, the politically shrewd Mr. Neall has managed to get along with most everyone.

Said Laura Green Treffer, chairman of the Anne Arundel Republican Central Committee, "Bobby grabbed the bull by the horns and said, 'This is the way it is; work with me,' and people are working with him."

Mr. Neall's most important victory so far has been persuading five of six county unions to forgo pay raises and extend their

contracts until next year. How long he can stave off labor unrest is uncertain, however. Members of education unions, who are at an impasse with the Board of Education, say they are withholding judgment on the executive until they see his budget.

Also, The Anne Arundel Taxpayers Association, a vocal, active anti-tax group, shows signs of disenchantment. At a public hearing on the budget last month, leaders of the group found fault with Mr. Neall for not going far enough in providing tax relief. They criticized him for violating a hiring freeze and for supporting only the minimum 10 percent cap on property tax assessment growth.

Mr. Neall said recently that the tax rate will not be lowered "unless money drops out of the sky." If his budget, due May 1, does indeed reflect a stable tax rate, tax revolt leaders almost certainly will be angry.

Still, Mr. Neall has survived his initiation unscathed. And, though he estimates his 1992 budget will be slightly less than last year's, major opposition seems unlikely if he keeps his promise not to raise taxes and to protect front-line teachers, police officers and firefighters from spending cuts.

Unless the economy improves more quickly than anyone anticipates, it likely will be 1993 before the executives can focus on their own agendas. Some political observers argue that it isn't fair to judge them until then. But how they survive their political troubles now will almost certainly determine the verdict in four years.

Elise Armacost is a reporter for the Anne Arundel County Sun, a suburban edition of the Baltimore Sun.