Congressman Thomas P. O'Neill, whose district includes Cambridge, is expected to announce this weekend he is endorsing Sen. Eugene J. McCarthy (D-Minn) for president, according to informed sources.

Hung Up

When asked for confirmation of the report early last evening, Cong. O'Neill hung-up without answer. His Boston office would neither deny nor confirm the report. By co-incidence, however, his office is preparing a new biography of the Congressman for release shortly.

O'Neill is pledged by law to McCarthy for the first ballot at the Democratic National Convention because of the Minnesota Democrat's victory in the April Massachusetts presidential primary. The Bay State Congressman, a member of the powerful House Rules Committee and an eight-term incumbent, is the first major Massachusetts Democratic office-holder to endorse McCarthy.

Vietnam Summer

Many expected O'Neill's move to McCarthy. He broke with the Johnson Administration on the War in Vietnam last August after a major anti-war canvassing campaign (Vietnam Summer) in his district aimed specifically at him. His call for de-escalation at the time surprised his House colleagues and reportedly angered President Johnson.

Nevertheless, O'Neill backed President Johnson for re-election early last December following a McCarthy effort at the time to win his backing. After Johnson withdrew in March, O'Neill refused to back either Humphrey or Kennedy.

Pressure

Again this summer liberals in O'Neill's ethnically heterogeneous district put pressure on him--this time to vote for McCarthy or at least against Humphrey. Thousands of letters supposedly were written urging him as a delegate to vote for the Minnesota Democrat. McCarthy forces made moves to organize a campaign to defeat him in the September Massachusetts Democratic primary.

The anti-O'Neill primary campaign by McCarthyites exists no longer. Instead a member of the "inner circle" of the U.S. House of Representatives has joined the McCarthy campaign.

Demonstration

As part of "National McCarthy Day" (August 15), Massachusetts McCarthy forces are organizing a massive demonstration on the Boston Common August 15 to show "the politician's of McCarthy's support by the people."