His $4.2 million war chest also dwarfs the resources of Robinson, who has raised less than $50,000 and plans to spend only $200,000 of his own money.

But it was not always so easy for Kennedy.

In 1994, Kennedy ran an extremely tough race against Republican venture capitalist Mitt Romney, spending more than $10 million to win reelection.

Last week, a worry-free Kennedy made a joint appearance with Romney at the opening of a Mormon temple in Belmont.

"You approach each campaign differently, depending on the environment, and it's much different than in '94," says Will Keyser, Kennedy's director of communications. "[Republicans] aren't fielding a candidate this year and the candidate that is on the ballot they don't support, so it's a very different situation."

But Keyser says Kennedy still plans to run "an aggressive campaign," viewing the election as a chance to educate voters about his accomplishments regarding health care, education, environment, civil rights and economic growth.

"Competition ebbs and flows," Keyser says. "The message is constant. It's not going to change and hasn't changed in his time in United States Senate."