WASHINGTON — Only a few hours had passed after the $45 billion merger between Comcast and Time Warner Cable was announced last week when an early voice emerged endorsing the giant deal.

“Win-win situation for American businesses,” said the statement from the United States Hispanic Chamber of Commerce.

It was the start of what Comcast executives acknowledge will be a carefully orchestrated campaign, as the company will seek hundreds of such expressions of support for the deal — from members of Congress, state officials and leaders of nonprofit and minority-led groups — as it tries to nudge federal authorities to approve the merger.

But what the Hispanic Chamber of Commerce did not mention in its statement praising the transaction was that it had collected at least $320,000 over the last five years from Comcast’s charitable foundation, which is run in part by David L. Cohen, the Comcast executive who oversees the corporation’s government affairs operations.