U.S. Rep. John B. Larson, D-1st District, intends to endorse Dan Malloy for governor Friday, citing Malloy’s support of campaign finance reform and his partnership with Comptroller Nancy S. Wyman.

The endorsement by Larson, who has represented Greater Hartford in Congress for a dozen years, comes as the Democratic race for governor has narrowed to Malloy and Ned Lamont.

Rudy Marconi, the first selectman of Ridgefield, ended his campaign today and endorsed Lamont, a Greenwich businessman who was the 2006 Democratic nominee for U.S. Senate.

Malloy and Lamont each have rolled out endorsements in recent days as they try to build momentum heading into the Democratic state convention on May 21 and 22.

Lamont recently announced the backing of two urban mayors, John DeStefano of New Haven and Bill Finch of Bridgeport, and Sam Gejdenson, a former congressman from the 2nd District.

Malloy, the former mayor of Stamford, countered today with the backing of Waterbury Mayor Michael Jarjura, who says he will bring with him all 49 of the city’s delegates to the convention.

A source familiar with Larson’s decision to endorse Malloy said the congressman will point to Malloy’s choice of Wyman as a running mate and his position on public financing.

Malloy is the only gubernatorial candidate who has raised the $250,000 in small-dollar donations to qualify for public financing under the Citizens’ Election Program.

Lamont has opted out of the voluntary program and is expected to contribute heavily to his own campaign.

Endorsements typically have their maximum value among party insiders, such as the nearly 2,000 delegates who will gather next Friday and Saturday at the Democratic convention.

“There’s endorsements, and there’s endorsements,” said Richard Foley, the former Republican state chairman. “A congressman brings weight. A state chair brings weight. A governor brings weight.”

On the Republican side, Gov. M. Jodi Rell has yet to make an endorsement, though she has shared the spotlight in recent months with Lt. Gov. Michael C. Fedele.

“Clearly they are not as meaningful as they were 25 or 30 years ago. What they were used for 25 or 30 years ago was to prevent a primary, now they are used as an enhancement,” Foley said.

Mark is the Capitol Bureau Chief and a co-founder of CT Mirror. He is a frequent contributor to WNPR, a former state politics writer for The Hartford Courant and Journal Inquirer, and contributor for The New York Times.