An Anne Arundel County Circuit Court judge yesterday dismissed a lawsuit filed by former state senator Tommie Broadwater Jr., who alleged that a proposed constitutional amendment on the Nov. 6 ballot would illegally keep him from running for his old seat in 1986.

Judge Bruce C. Williams rejected claims by Broadwater, who was convicted of food stamp fraud, that the amendment to the Maryland Constitution is aimed solely at keeping him out of political office and is, therefore, illegal.

If approved by the voters, the amendment would prohibit persons who are not registered voters from holding elective office. Broadwater cannot register to vote until his probation sentence for the fraud conviction ends in 1988, and thus is ineligible to run for office as the endorsed candidate of a political party until then.

But under a loophole in current law Broadwater could run in 1986 as an independent and has filed a petition in Prince George's County to do so. The amendment is intended to close the loophole, legislators said during debate on it in the General Assembly.

Williams found that while "the focus of the amendment might have occurred as a result of Mr. Broadwater . . . the focus on a provision isn't enough to say. . . it's directed at him."