As money pours in and candidates leave, Gov. Michael S. Dukakis is well on his way to becoming the front-runner for the 1988 Democratic presidential nomination.

The rise in the perception of the governor's chances is based both on the current cachet of candidates that project images of clean living, as well as Dukakis's ability to build a successful political and fundraising organization.

In past months the scrutiny of candidates' past and personal lives have dominated the Democratic political campaigns making the public's view of candidate's personal behavior all the more important. Last spring former Colorado Sen. Gary Hart withdrew from the campaign due to reports that he spent the night with a woman not his wife. And last week Delaware Sen. Joseph Biden left the race after it was revealed that he had plagiarized in his speeches.

Meanwhile Dukakis, who is known to avoid drinking and smoking, has raised the most money out of all the Democratic candidates, according to figures released today.

"The race is poorer without Hart and Biden, both [candidates] made very important contributions to the presidential campaign debates, and both will be missed," said Dukakis's Press Secretary Steven J. Akey.

"But our campaign will go on as planned, we're moving straight ahead," Akey added.

In a random poll of 15,000 people across the nation, conducted earlier this month, Dukakis recieved a 22 percent favorability rating. Fourteen percent had favorered Biden, said Jim D. Murphy, the head of Cambridge Reports, a national public opinion research center that did the poll for a local television station.

Dukakis is practically even in the poll with Rep. Richard Gephardt (D-Mo.), who has a 23 percent favorable rating. The only candidate with a higher figure is the Rev. Jesse Jackson, who received a 33 percent favorable rating. But Jackson also had the highest unfavorable rating of 57 percent.

"Dukakis has a bit of an edge now, but it's too early to put in to the terms of a horse race," Murphy said. Another poll of the Democratic candidates is planned for early December.

Dukakis campaign aides said while they are pleased by the governor's strong showing in many states, it is too early to predict who will be the front-runner. Campaign strategisits said they will persue the same campaign plan, regardless of the impact of Biden's withdrawl.

"The governor's central message is, and always has been, his commitment to economic opportunity for all Americans," Akey said. "We don't have to stress the governor's personal character because [his character] comes through very clearly."

But the issue of character has been an important plus in the governor's campaign. "If the president was chosen based upon international affairs, defense strategy or charisma, Dukakis wouldn't have a chance," said Boston political consultant Michael S. Goldman. "But since national issues, competence, honesty and personal integrity are now the issues, Dukakis will do well."

Other candidates are also sharpening their public image record. Illinois Sen. Paul Simon is running on a "straight-arrow" image by publishing all of his financial statements, and claiming that he will not give a speech that he has not written or at least revised himself, said Simon's Press Secretary Jim Killpatrick.

As personal integrity is emerging as a key factor in the races, some politicians fear the scrutiny will scare potential candidates.

"The American public is very traditional, and in times of crisis, such as during the Iran-Contra hearings, traditional values take greater prominence," said Jan C. Smith, assistant to Marttila and Kiley Consultants, Biden's political consultants. "But the expectations that people have about candidates are too strong and too burdensome."

"Personal issues are an important factor, but there is definitely an overemphasis of it now," said State Rep. Richard J. Rouse (D-Boston). "Too much scrutiny will dissuade otherwise capable people from persuing politics."

The focus on one's personal life will have a "chilling effect on people who want to enter public life," said State Sen. Thomas P. White (D-Worchester). "It will inhabit the performance and the ability for us to do our duties today," he said.

The Dukakis straightarrow image has been selling well. He has shown great success in fund raising, which helped him enter the first tier of candiates, Goldman said.

Dukakis raised $4.6 million in the first quarter of his campaign from April to June this year, Akey said. The governor is expected to have netted a total of $8.5 million for his campaign, which includes a record $3.9 million for the second quarter.

A significant part of Dukakis's support comes from his ability to prove himself in other candidate's home turf, Goldman said. "Biden was predicted to raise the most money, but Dukakis eventually did, Gephardt was supposed to get the majority of labor support, but both [candidates] are closely battling [for the labor vote], and Babitt was expected to get the Hispanic vote in the South, but Dukakis came in, spoke a few words of Spanish, and walked away with a straw poll victory," Goldman said.