Running against a conservative white challenger four years ago, he won in a landslide, with 74 percent of the vote.
The winning majority was 5.7% over the Conservative challenger.
Mr. Forbes is the only credible conservative challenger in the race.
During the campaign, Jubelirer's more conservative challengers attacked him on abortion.
Three moderate Republicans holding statewide jobs also won easy re-election, two of them after beating back conservative challengers in the primary.
A Connecticut senate candidate has a solution: a talisman to ward off a conservative challenger.
But others argue that discrediting the conservative challenger, even as a protest candidate, was becoming imperative.
His conservative challenger, Angela Merkel, has put job creation and tax changes at the top of her agenda.
The margin of victory between the liberal and his conservative challenger was closer than in 2004, but McGuinty eventually came out on top.
But the conservative challenger said he had "other objectives" besides winning the nomination and would continue campaigning through the California primary on June 2.