The mayor was having problems with Queens Republicans, who were putting a local candidate up against him, even as the other Republican county chairs fell into line. A looming subway fare hike was poised to present unpleasant bumps in his first re-election effort. Some outer-borough conservatives were calling him a mayor for Manhattan, while many blacks, Latinos, and liberal activists were expected to back other candidates.

But Mayor Koch was still cruising toward landslide re-election in 1981 at a speed that Mayor Bloomberg and his team would envy.

For all the obvious comparisons to John Lindsay’s troubled 1969 re-election and Mayor Giuliani’s iconic presence as his immediate predecessor, the mayor that Michael Bloomberg seems to admire and emulate most personally is a Democrat, Edward Koch. His administration is full of Koch administration alumni, including an influential deputy mayor, Patricia Harris, and Mr. Bloomberg’s chief of staff, Peter Madonia. Mr. Koch’s trusted first deputy mayor, Nathan Leventhal, oversaw Mr. Bloomberg’s post-election transition into City Hall, bringing a decidedly Democratic-establishment flavor to underlying layers of the Bloomberg administration. Mr. Bloomberg, like Mr. Koch, sees managerial competence as a main selling point of his administration, promoting political moderation and a bipartisan style of governance. But why has Mr. Bloomberg been less successful than Mr. Koch in winning over opposition?

In 1981, Mr. Koch’s first term was judged to be such a self-evident success after the fiscal crisis of the mid 1970s that he pulled a political coup by winning the nomination of both the Democratic and Republican parties and winning the general election with 70% of the popular vote against fringe Conservative, Liberal, and Unity party candidates.

But where Mr. Koch succeeded in splintering his limited opposition, Mr. Bloomberg’s opposition is increasingly emboldened in its goal of defeating the mayor. A New York Times/CBS poll released on Wednesday shows a vulnerable incumbent with 43% job approval, losing to an unnamed Democrat by a 52% to 30% margin.

Historical precedent is the most useful measure for gauging the potential for success in politics, and a glance at other recent first-term mayors running for re-election suggests that Mr. Bloomberg has reason to be concerned about his prospects. At this stage in Mr. Giuliani’s 1997 re-election effort, the mayor enjoyed a 54% job approval rating with a unified Republican base and a series of high-profile Democratic endorsements. At this point in 1981, Mr.Koch could point to praise from the Republican City Council minority leader, Angelo Arculeo – who appreciated the mayor’s appearances at his Bay Ridge Republican Club – and his former Republican opponent for mayor, State Senator Roy Goodman, who described Koch as “an outstanding mayor” and advocated for his endorsement by the party. There is no such outpouring of support for Mr. Bloomberg from high-profile elected Democrats, despite his best efforts at the expense of his own party.

In an interview, Mr. Koch reflected upon his 1981 race and Mr. Bloomberg’s prospects in this year’s election. He attributed his success at winning over Republican leaders in his first re-election to his advocacy of “middle class values” and ability to reach out and work with moderate Republican, as well as Democratic, political leaders. Mr. Koch strongly supports Mr. Bloomberg and believes he will be ultimately re-elected, but acknowledges, “He’s not been able to connect with Republicans because they see him as a Democrat. He is someone who is a welcome technocrat, who wants to get things done without regard to party. He doesn’t use appointments and other things available to a mayor to get someone to go along – whereas I did,” mentioning frequent invitations of local political figures to Gracie Mansion “to make them feel they were part of the city.”

The political spin the Bloomberg administration has attempted to deploy around the Republican defections is that they are disgruntled patronage seekers. This has only further infuriated local leaders, who complain that they can’t even get their phone calls returned by City Hall. There is instead the sense that Mr. Bloomberg has failed to reach out to local Republicans even as much as Mr. Koch did, and instead rewarded critics and Democrats who are now mobilizing against him because they see a better opportunity for more direct access to power. Even Democratic clubs that have endorsed Republicans in the recent past – such as the Queens Highway Democrats – are now supporting Democratic candidates for mayor.

In contrast to Mr. Koch and Mr. Giuliani’s strong first-term poll numbers, Mr. Bloomberg’s numbers currently more closely resemble those of David Dinkins, whose job approval ratings never exceeded 47%. An even more troubling trend is evident in the gap between people’s sense that the city is broadly moving in the right direction but the mayor deserves no special credit for this. The most successful New York mayors have historically been those who occupied the office with larger than life personalities, becoming symbols of their city. This was true for Fiorello La Guardia, Mr. Koch, and Mr. Giuliani. Mr. Bloomberg, in contrast, has become seen as “the Dispensable Mayor,” allowing Democrats to effectively blur contrasts on crime or fiscal policy while they chip away at key constituencies who feel little loyalty to this administration.

“My advice is simple,” says Mr. Koch. “Get out there and touch more flesh, get reporters to interview you one on one.”

“He’s a marvelous self-salesman, but a reticent kind of guy, shy,” says Mr. Koch. Mr. Koch reaches back to a line he used on the 1981 campaign trail as a final bit of advice: “If everybody who disliked me got together, you could throw me out. I’ll get a better job, but you won’t get a better mayor.”

“I’m sure that’s his feeling,” Mr. Koch recommends. “He should more strongly convey it.”