Almost every year since she arrived in the Maryland legislature in 1979, Del. Joan B. Pitkin (D-Prince George's) has introduced legislation to subsidize basic telephone service for the poor. Each time, the General Assembly has rejected the so-called "lifeline" bill.

This year, things are different. For one, the telephone service would be funded by a tax credit to the phone company rather than by ratepayers. More importantly, the lead sponsor of the House version is now House Speaker Benjamin L. Cardin rather than Pitkin. Suddenly, the bill has wings and is flying toward enactment.

The Cardin factor, some legislators say, is a phenomenon of the 1985 legislative session. Eighteen months before the Democratic gubernatorial primary in which he expects to be a candidate, Cardin is perceived by some lawmakers to be subtly using this session to run up the value of his political stock.

Throughout the halls of the Maryland General Assembly, there is talk that the 41-year-old legislator from northwest Baltimore is behaving differently as the 1986 primary draws nearer. Usually such talk is sotto voce. But occasionally it breaks out in the open, as it did when the Constitutional and Administrative Law Committee gathered to vote on the speaker's lifeline bill.

Del. Frank Pesci, suggesting that his Prince George's County colleague had been shouldered aside on the lifeline bill, insisted that Pitkin be added as a cosponsor.

"I realize she's not running for governor, but the concept has been hers for a long time," Pesci told the committee chairman. Pitkin got her cosponsorship.

Said Del. Gerard F. Devlin (D-Prince George's), who sits on the Ways and Means committee, "Cardin's involving himself in more areas now. He's appeared more before our committee than in the past."

Cardin, admitting that he is "very sensitive" to such talk, argues that he is the victim of perceptions that have little to do with the truth. To rebut the widely held notion that he has been testifying more frequently on legislation this year, for example, he had his staff dig through his office records to show that is not the case.

Yet in politics, perceptions are often what matters most. And the perceptions in this case dovetail nicely with Cardin's strategy before he formally announces his candidacy, devised by professionals who are now guiding him. That plan calls for an extended period of trying to convince state "opinion leaders" that he is a candidate who can win.

Cardin acknowledges, "I'm running two campaigns. Right now I'm running a campaign towards the campaign, to become a credible candidate, to position myself. That's not with the voters, it's with the politicos."

As speaker and would-be governor, Cardin plays to his already considerable strength as a consensus politican, accommodating in a balanced fashion the wide range of interest groups and jurisdictions that annually compete for power and plunder during the 90-day legislative sessions.

Among the interests he has attempted to help this year are homeowners. For the past four years, Del. Constance A. Morella (R-Montgomery) has introduced a bill to expand the homeowners' tax credit program by raising from $40,000 to $50,000 the ceiling on property assessments that qualify for the property tax break. Such a bill would add about 4,500 homeowners statewide to the program, about half of them in Montgomery County.

Every year, said Morella, the bill to broaden the program languishes on the Ways and Means Committee "wish list," which is a polite way of saying it's a commendable idea that can't be funded.

This year, the bill is being sponsored by the speaker and it has moved from the wish list to the must list. It passed Ways and Means and the full House with ease, and is expected to be enacted.

"Somebody came to me and said jokingly, 'Is there anything else you have that the speaker can sponsor?' " said Morella.

There are other examples:

It was Cardin who convinced the Hughes administration to include in its fiscal 1986 budget the operating expenses of senior citizen centers, a departure from past practice of state funding only for capital costs. Cardin sought $1 million; Hughes agreed to $500,000.

In the Senate, the funds were redirected to expand an existing program for the elderly known as Gateway II. When a Baltimore County delegate sought to introduce the same amendment on the House floor, Cardin brought him into his office and convinced him not to.

Cardin introduced legislation to provide better death benefits to the spouses of correctional officers killed in the line of duty. Cardin made that commitment during a press conference with state employe union leaders last fall at the height of a crisis at the Maryland Penitentiary in Baltimore after the murder of a guard.

Cardin has been particularly attentive to regional and local needs, more so than in the past, say many legislators. He has been an ardent advocate of economic development projects for Western Maryland such as the development of a state conference center and completion of the National Freeway.

He has taken a more active role in shaping the capital budget that determines which jurisdictions get money for special projects.

For example, he has been a key player in efforts to assure that Montgomery County gets additional money for schools and some assurances its road problems will be eased. And he has begun regular meetings with the chairmen of the county delegations to assess their concerns.

"Ben's strategy this year," concluded one delegate who asked to remain anonymous, "is to take any issue that is going to be hot and go testify for it, so at the end of the session he can say 'we constrained health care costs, helped old people, fixed up higher education and solved the prison crisis.' The difference this year is his visibility and his overriding concern with how everything plays."

Not so, insists Cardin. His sponsorship of such things as the lifeline bill represents the position of the House leaders including committee chairmen and not his own political agenda, he says. He adds, "The most important thing for me to do is have a successful legislative session."

"As you get closer to the election, people associate more of what you do with being political," he continues. "That is a hazard we all live with. But it is absolutely not occuring . . . . There's one thing I truly won't do. I won't compromise my position as speaker for anything."

Cardin has been subject to more than the usual pressures this year. Delegates looking for help with their bills have added a new pitch: Jump on this issue and it will play well in 1986. As Del. Daniel Long (D-Eastern Shore) said recently, "He's a great cosponsor." Cardin estimates he has turned down a dozen such suggestions this year.

Despite Cardin's disclaimers, the perception persists that he is consciously trying to get out front on issues that would be politically beneficial.

Occasionally, Cardin has stumbled. Last fall, for instance, he promised the Maryland Chamber of Commerce during its annual fall retreat at Bedford Springs, Pa., that the legislature would override Hughes' veto of a bill giving the General Assembly power to overturn executive agency regulations.

Cardin's pledge delighted the businessmen, but ran into stubborn opposition in the state Senate. Senate president Melvin A. Steinberg had not been consulted by Cardin, and balked at the veto override. That has left Cardin scrambling for much of this session to devise a face-saving compromise on the issue, and only a much-weakened version is likely to emerge.

On the second floor of the Maryland State House, where the governor and his staff work, there is the feeling that Cardin's ambitions have been a wild card in relations between the executive and legislative branches.

Between Cardin and Gov. Harry Hughes -- who is also positioning himself for 1986, when he is expected to run for the U.S. Senate -- there is an added degree of competition.

At one point during the ongoing debate over legislation to give Citicorp full banking privileges in exchange for establishing a credit card center in Hagerstown, the Hughes administration felt Cardin broke a confidence by revealing to reporters the outline of administration amendments designed to placate opponents.

The governor quickly called an impromptu press conference so he would not be preempted.

In running against the other all-but-announced gubernatorial candidates -- Attorney General Stephen H. Sachs and Baltimore Mayor William Donald Schaefer -- Cardin has his work cut out for him. No presiding officer of either the House or Senate has been elected governor in modern Maryland political history, except for Marvin Mandel, who was initially elected by the legislature when Spiro Agnew resigned to become vice president.

"There's something about the legislature that you don't get visibility no matter what you do," said Del. Timothy F. Maloney (D-Prince George's County). "You are one of 188 legislators. It's hard to become larger than the institution, and if you do, the institution has a way of reining you back in.