New Haven Mayor John DeStefano Jr. has always been an underdog in Connecticut’s gubernatorial race. But now that Republican Gov. M. Jodi Rell has declared she will not accept contributions from state contractors and lobbyists, DeStefano and fellow Democratic candidate Dannel Malloy are in an even weaker position to challenge the popular incumbent.

Rell’s decision parallels a discussion in the state legislature regarding public campaign financing and a potential ban on contributions from lobbyists and contractors. Her announcement is a step in the right direction for a state that has faced corruption at the highest political levels.

From a political perspective, this action is also a brilliant move for Rell. It not only distances her from the legacy of imprisoned former Gov. John Rowland — under whom she served as lieutenant governor — it strengthens her footing in the campaign finance debate, since both of her Democratic opponents have accepted contributions from contractors who could use political favor.

Rell’s high profile and stellar approval ratings, in contrast to the relative statewide anonymity of her opponents — both of whom are mayors — make it far easier for her to reject donations from contractors and lobbyists. Through the skillful use of state-funded advertising designed to market Connecticut as an attractive business destination, Rell has also prominently portrayed herself as a friendly figure to the business community. She does not need soft money as much as her opponents do.

At little cost to Rell, refusing lobbyist contributions puts increased pressure on DeStefano to exercise caution with regard to campaign finance.

The mayor has already faced criticism for soliciting donations from city employees and contractors who stand to gain financially from his favor. But so long as there is no overt quid pro quo, DeStefano’s solicitations are not illegal, and his campaign may well need these contributions to remain competitive. Still, the mayor would be wise to ensure that decisions to award lucrative city contracts do not correlate to large campaign donations from employees of the firms being contracted.

More importantly, it is time for the DeStefano campaign to recognize that its efforts to call Rell’s integrity into question are probably futile. Rell’s track record indicates that she has made a substantive commitment to avoid special interest politics and to reform the state’s political institutions. The largely negative campaign DeStefano has run so far — distributing a compact disk with information designed to link Rell to Rowland, for example — cannot succeed on these grounds.

Rell has scored an early victory by taking the lead on campaign finance reform. Moving forward, DeStefano’s campaign should focus on presenting a positive message for Connecticut, detailing progressive ideas to invigorate the state’s economy and highlighting initiatives that have yielded significant gains in safety and education in New Haven during his tenure. If he hopes to win the gubernatorial election, DeStefano will have to focus on his own ideals and his own track record, not Rell’s.