Baltimore County Executive Donald P. Hutchinson formally filed as a Democratic candidate for the U.S. Senate here today, surrounded by friends and supporters from the Baltimore area whom he said underscored his position as a candidate who sticks close to his roots.

Hutchinson, a former Maryland state delegate and senator, said, "What we're moving toward, of course, is to combine that county courthouse influence with the statehouse influence, [and] to take that to the halls of the U.S. Capitol building . . . . It is the influence of good, fiscally responsible government, that knows how to set the tone of government, that knows how to take responsibility for its decisions."

Hutchinson used his filing today to introduce his campaign supporters. The group is heavily drawn from the ranks of Baltimore County and rural Maryland officeholders who have adopted Hutchinson's U.S. Senate bid as their best chance to "get somebody in there who really knows what their issues and concerns are," said campaign manager Donald Fry, a Harford County lawyer.

Hutchinson's announcement came amid a flurry of campaign activity by his announced Democratic primary opponents, Reps. Michael D. Barnes and Barbara Mikulski. Each has led forays into the other's base of support.

Mikulski, like Hutchinson, appeared in Annapolis for the second straight day today to meet individually with state lawmakers. She had come from a speech at the Propeller Club, a business executives club in Baltimore, where she discussed economic development strategies. Having already made one notable trip to the Washington suburbs last month for a Bethesda fund-raiser hosted by U.S. Rep. John Dingell (D-Mich.), an influential committee chairman, the East Baltimore member of Congress is journeying to Prince George's County at the end of the week to discuss economic development and meet with citizens there.

Barnes, a Montgomery County lawyer, has been commuting to Baltimore City and County in recent weeks, including a visit to Essex, one of Hutchinson's bases, two weeks ago. On Thursday he will venture into Mikulski territory with a meeting at a Baltimore Democratic club smack in the middle of her 3rd Congressional District.

Hutchinson has been noted for his strident attacks on his opponents in recent days, including comments he made in an interview Monday with The Washington Post, where he said Barnes and Mikulski, both of whom lead him in the polls, lacked his ability to make tough decisions and had accomplished little in their years in Congress. He reiterated those comments today, saying the two govern "through rhetoric and not performance . . . [the two candidates] who have never attempted to balance a governmental operating budget; you don't reward them, you send them home where they belong."

Barnes' spokesman dismissed Hutchinson's comments, saying they were "obviously not based on fact."