“It is not possible to be traitor to the US by supporting Russia.”
Sure it is.
18 USC Ch. 115: TREASON, SEDITION, AND SUBVERSIVE ACTIVITIES
https://uscode.house.gov/view.xhtml?path=%2Fprelim%40title18%2Fpart1%2Fchapter115&edition=prelim
Nothing in §2381 requires the US to be engaged in a declared war with an enemy in order to qualify support for such enemy as treason.
Further, precedent setting broad applications of §2386 have been applied to individuals whose public activities are proven to be aligned with the interests or policies of hostile foreign powers.
Arguably, someone who is indicted for §2386 violations could be then prosecuted for §2381 violations.
Note that I am not assuming a conviction, just that an indictment could easily occur given the right circumstances and the political will to execute the prosecution.
§2381. Treason
Whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States.
We have no “enemies” currently defined by the USA.
Our only “enemies” are defined by a declaration of war.