Two readers have complained that the decision to make today's inauguration a "fancy pants" event is "elitist and undesirable." I must disagree.

Our critic wrote, "I object to a dress code that makes it necessary for even those with extensive wardrobes to go out and rent a prescribed costume. A true 'government of the people' would not require morning suits to be worn in an era in which not one man in a thousand owns a morning suit."

Pish tush, my good fellow. For thousands of years it has been the sustom to don fine raiment to mark special occasions. On ordinary days we wear ordinary attire, but when we attend weddings, coronations, religious services and similar events we wear our finest garments. Even a government of the people can dress up in its Sabbath vest as a mark of respect for a presidential inauguration.

Politically speaking, this is our wedding day. During the campaign, Ronald Reagan may have been regarded by some as "that actor." But today he becomes our president and our best hope for leadership toward a better tomorrow. We must pray for him and support him, for our honeymoon begins today.

Like it or not, we are wedded to him, perhaps for four years, perhaps for eight, perhaps until death parts us. If Reagan's decisions are wise, or lucky, we will prosper; if they are not we face troubled times.

So let us put on our fanciest duds and our soberest faces and give heed as the 39th man to hold the office places his left hand on a Bible, raises his right hand to heaven, and says, "I, Ronald W. Reagan, do solemnmly swear that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."

No president since George Washington managed to sustain the honeymoon period for eight years, or even four. But this is no time for negative thoughts. This is our wedding day, and whether we are in proper attire at the ceremony or watching TV in blue jeans, the groom has our sincere good wishes. NO WAY TO RUN A RAILROAD

Incidentally, did I tell you I received a letter from Reagan yesterday? Well, I did.

I refer to L. Howard Reagan of Potomac, of course, not Ronald W.

District Liner Reagan reports: "Amid the stores on the mall at L'Enfant Plaza are a few business offices, and I have noticed that the foyer of one of these offices sports a TWA poster on the wall.

"you say,'So what?' Well, the office I am referring to is that of the United States Railway Association".

How sad! In business, an industry usually regards its competitors as "the enemy," but American railroads have litle interest in carrying passengers. They make their money on freight and consider passengers a nuisance. They wish all passengers would travel by air.

The railroads permitted passenger service to fall into such desrepair that it would have vanished if the government hadn't stepped in to subsidize it.

The airlines were young, vigorous and hungry for business. It didn't take them long to learn to haul passengers at a profit.

Now air traffic nears saturation, population density pushes airports farther and farther from urban centers, householders complain about noise along flight paths, and architects fear that vivration caused by aircraft will bring the Capitol dome crashing to the ground. But, alas! The average American is now out of the habit of using trains.

I wish there were some way to get our railroads interested in reclaiming their lost passenger business. Above or below ground, between Eastern cities or between a city and its bedroom communities, a railroad is the ideal mode of short-haul mass transit.

Today we need this efficient commuter service more than ever because central city populations are shrinking and people are moving out into the suburbs and beyond. But in most parts of the country, good rail passenger service does not exist.

For the commuter, the problem is especially easy to comprehend: If there is no rail service between Washington and Cleveland, airlines will fill the void. But if there is no rail service between downtown Washington and Round Hill, or between downtown Washington and Lower Marlboro, the airlines will not fill the void.