Consider Victor Berger, elected as a Representative from Wisconsin in 1918. The House refused to let him serve, since he was a convicted felon (he violated the horrid Espionage Act) and war opponent.
This was justified by Section 3 of the Fourteenth Amendment:
> No person shall be a Senator or Representative in Congress, or elector of President and Vice President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof.
Following the logic that birthed the foul Espionage Act, "not wanting to go to war" = "aiding the enemy", hence Berger wasn't seated in 1919 nor, after rewinning the election, in 1920.
He was a Socialist, not a Communist. Not that it really matters; an anti-war Communist would have had no better chance.
That said, I'm as confused as you about jjoonathan' comment, as removing (or at least preventing) elected officials from holding office was at best a contingency plan during the Red Scares.
This was justified by Section 3 of the Fourteenth Amendment:
> No person shall be a Senator or Representative in Congress, or elector of President and Vice President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof.
Following the logic that birthed the foul Espionage Act, "not wanting to go to war" = "aiding the enemy", hence Berger wasn't seated in 1919 nor, after rewinning the election, in 1920.
He was a Socialist, not a Communist. Not that it really matters; an anti-war Communist would have had no better chance.
That said, I'm as confused as you about jjoonathan' comment, as removing (or at least preventing) elected officials from holding office was at best a contingency plan during the Red Scares.