The photographs on the wall of the committee chairman's office date to 1975. In the first one, a round-faced freshman senator wearing a wide tie occupies a desk at the back wall of the Senate chamber, far removed from the spotlight reserved for then-Senate president Steny Hoyer.

In this year's photograph, State Sen. Thomas V. Mike Miller Jr. of Prince George's County sits front and center. His curly hair is graying; his tie, silk, is narrower; his pinky ring glints in the foreground.

Miller's prestige -- his seat now is directly in front of Senate president Melvin A. Steinberg's gavel -- has come by dint of his shrewd political instinct and a measure of good fortune. Today, he is chairman of the the influential Senate Judicial Proceedings Committee. He controls the votes of seven Prince George's senators and runs what remains of the Democratic Party organization that dominated county politics in the 1960s and 1970s.

Alone, Miller has filled the vacuum left by three-term congressman Hoyer's departure from the daily, local political scene, and the absence of the one-time Democratic kingmaker and now president of the Greater Washington Board of Trade, Peter F. O'Malley. Although he still takes some cues from Hoyer and O'Malley, Miller said, "When it comes time to tell somebody they really should step aside . . . the job falls to me."

Miller also has risen in the legislature to become Steinberg's right-hand man, someone the president describes as his "enforcer," and one of the most powerful politicians in Maryland.

Steinberg, who readily admits that he would not be president without Miller's help, identifies the Prince George's senator as his most likely successor. Several of Miller's colleagues agree. Others mention his name as a potential candidate for lieutenant governor.

Miller, 43, listens to all of the musings about his political future but says he is content with his current role. He has gone unchallenged in his past two Senate races. Politicians from around the state routinely curry favor with him, hoping that Miller's approval will guarantee success in the state's second most populous county, which is heavily Democratic.

Miller's accumulation of power, and his tactics for keeping it, are legendary in the State House.

Blair Lee IV, who served as Montgomery County's chief lobbyist for six years here, remembered bumping into Miller in a State House corridor after Miller discovered that Lee had been secretly working to defeat a Prince George's County bill.

"All of a sudden I saw this curly-haired guy coming around the corner, he sees me and puts both hands on my lapels and backed me against the wall," said the 6-foot-3-inch Lee. The message, he said, was to lay off the bill.

"He's got an Irish temper and an Irish humor, but you never know which one he'll be in at that minute," Lee said.

Mike Miller, as everyone calls him, is alternately vilified, feared and respected by his colleagues. He is an inveterate backslapper in the finest tradition of Maryland politics. He sends flowers to female legislators, routinely calls them "darlin'," and uses his broad southern Maryland accent and a studied country charisma to dull the sting of insults he dispenses liberally.

Miller's reputation stems not only from his aggressive style, but also from his brand of conservative Democratic politics. When he first ran for the House of Delegates in 1970, he opposed liberalized abortion laws and increased gun control while favoring the concept of tuition tax credits for parochial schools.

Over the years, his positions on these issues have remained essentially unchanged.

But in other areas, Miller watchers say, there has been a moderation in his views, coinciding in part with a shift in the political winds in the county, which voted for Jesse L. Jackson in the 1984 presidential primary.

For Miller, who has alienated some blacks and women as his power has grown, the emergence of a potentially powerful black majority in his home county looms as the biggest question mark in his future.

"Mike's district used to be a simple, rural, white conservative one," said Del. Gerard Devlin (D-Prince George's).

"Now it's suburban and it's really urbanizing. I think he's become much more moderate."

The committee he chairs in Annapolis has approved bills that would ban the death penalty for juveniles and make penalties for child abuse harsher. As a member of the Senate leadership, Miller has risked alienating friends and relatives on controversial bills.

Three years ago, he made enemies in his father's alcoholic beverages industry when he voted to increase the drinking age. Two years ago, he angered people in his sister's teaching profession when he voted to place a cap on state employes' pensions.

"It's a sure sign of failure when you try to please everybody," he reasoned.

Last year, however, when he killed a bill that could have expanded the number of blacks on the local board of elections, he was accused of being unwilling to share power. "He did not show any understanding or sensitivity to the message of the Jackson candidacy," said Del. Albert Wynn, a Prince George's Democrat and a member of Jackson's Rainbow Coalition. "The message of the Jackson candidacy was power sharing and greater participation involving more people. That was a philosophy that he never embraced."

Esther Miller named her son after his father because that is the way it was done in 1942. "But from the day of conception I called him Mike," she said.

That her Mike, whom she described as a "so-so student" in pub- lic school and at the University of Maryland, would one day become a statewide political power broker never occurred to Esther Miller.

But in Clinton, a southern Prince George's community with a single stoplight, the Millers have been well known since the turn of the century. At the main intersection is the B.K. Miller Super Liquors store run by his father, Thomas Miller Sr. A block away is a branch of Citizens Bank and Trust Co. that occupies Miller land. His father sits on the bank's board. Miller, his wife Patricia and their five children still live there.

"He had the early advantage in politics of being the son of a father who knows everybody and a mother who is a saint," said Thomas Farrington, who worked with Miller in the Young Democrats in the 1970s. "He had more political contacts at 18 years old than I've ever had any time I've been alive."

Miller is the eldest of Esther and Thomas Miller Sr.'s 10 children. His sister Nancy, who practices in the same Clinton building where Miller has his own legal office, calls him "bossy." His mother calls him a "male chauvinist pig" and blames herself that he is.

He did not get his conservative politics, however, from Esther Miller. She believes in Medicaid funding for abortions and said she felt proudest of his work in Annapolis when he publicly denounced a bill that would ban the sale of obscene records to minors.

"He is less conservative than he gives the appearance of being," she said.

Miller got his first taste of politics as a chauffeur for a Republican candidate for governor during the summer of 1962. For $50 a week, he traveled the state, met people and learned the fine political art of handshaking.

At his mother's urging, he later went to law school. "She was determined that I was not going to work in the store," he recalled recently.

After graduation in 1967, he worked briefly for a county judge until he was offered a bill-drafting job working for the county's House delegation here.

"After about six months I felt that maybe I could do the job as well," he said.

By that time, he had met Hoyer and O'Malley. When they went shopping for a strong south county candidate to fill their ticket in 1970, Miller suddenly stepped from obscurity into elected office.

"One, he was bright," Hoyer said. "Two, he doesn't blink easily. Three, he's a good politician. While he's a tough politican, he's also someone who understands the necessity for accommodations with others."

But even after he was elected to the Senate in 1974, Miller operated in Hoyer's shadow.

"Miller was always complaining about O'Malley and Hoyer," said Prince George's Del. Timothy F. Maloney. "That more than anything shaped Miller. He wasn't in control."

It was in 1978 that Miller got his first chance to wield power. Hoyer ran for lieutenant governor with Blair Lee III but lost to then-secretary of transportation Harry Hughes.

The same year, Democratic County Executive Winfield Kelly lost a bitter race against Lawrence J. Hogan, a Republican.

"Mike filled the vacuum," Hoyer said. By the time Hoyer won a special election to Congress in 1980, Miller was running the county organization, and in 1982 he solidified his control in the Senate by orchestrating the defeat of Howard County Sen. James Clark as president.

"Mike's influence goes further than Prince George's County," said Sen. John C. Coolahan (D-Baltimore County).

"He can grab off a few votes here and there."

Baltimore County's Steinberg, who replaced Clark, explained Miller's success: "He is volatile, very emotional, a person who is extremely candid in his expression, but who possesses a tremendous ability not to offend people while criticizing them."

County Executive Parris Glendening, Miller's chief political rival in the county, has been a frequent target of Miller ridicule. In 1983, when Miller engineered a Democratic Central Committee vote to replace former state senator Tommie Broadwater with then-Orphans' Court Judge Decatur Trotter, Glendening called Miller's tactics "an arrogance of power."

Miller responded by comparing Glendening to a species of ape.

Miller and Glendening support Baltimore Mayor William Donald Schaefer for governor and have been meeting to talk over the possibility of fielding a common ticket in the county, with Schaefer at the head.

"It certainly would not be a love relationship," Glendening said of his new working agreement with Miller. "But it's one of mutual respect. He's going to be around for a while, and I'm going to be around for a while."

Neither faces opposition yet for reelection this year. But a coalition of Miller detractors, including Broadwater and Secretary of State Lorraine Sheehan, are encouraging County Council member Sue V. Mills to challenge Miller. Mills said she is thinking it over.

Broadwater, who spent four months in federal prison on a food stamp fraud conviction in 1984, remains bitter toward Miller, who masterminded passage of a bill that prevents him from seeking his old seat this year.

"Mike is very cool, you know," Broadwater said recently. "He's got the bush Afro-type hair style . He looks young. He can sing our songs. Mike knows more about black songs, black life and black artists than any black person I've ever talked to. He can dance. He appears to be with you. If you don't know him, you'll think he's the best of buddies. But he will stab you in the back."

Miller said he has "a very special place in my heart" for Broadwater. But when Broadwater's comments were repeated to him, Miller's eyebrows rose and his eyes lit up. Then he grinned and said: "That's not a bad analysis."