Is it a crime without criminal intent? Not for the crimes you are probably thinking of.
18 U.S. Code § 373 - Solicitation to commit a crime of violence
(a) Whoever, with intent that another person engage in conduct constituting a felony that has as an element the use, attempted use, or threatened use of physical force against property or against the person of another in violation of the laws of the United States, and under circumstances strongly corroborative of that intent, solicits, commands, induces, or otherwise endeavors to persuade such other person to engage in such conduct, shall be imprisoned not more than one-half the maximum term of imprisonment or (notwithstanding section 3571) fined not more than one-half of the maximum fine prescribed for the punishment of the crime solicited, or both; or if the crime solicited is punishable by life imprisonment or death, shall be imprisoned for not more than twenty years.
(b) It is an affirmative defense to a prosecution under this section that, under circumstances manifesting a voluntary and complete renunciation of his criminal intent, the defendant prevented the commission of the crime solicited. A renunciation is not “voluntary and complete” if it is motivated in whole or in part by a decision to postpone the commission of the crime until another time or to substitute another victim or another but similar objective. If the defendant raises the affirmative defense at trial, the defendant has the burden of proving the defense by a preponderance of the evidence.
(c) It is not a defense to a prosecution under this section that the person solicited could not be convicted of the crime because he lacked the state of mind required for its commission, because he was incompetent or irresponsible, or because he is immune from prosecution or is not subject to prosecution.
18 U.S. Code § 2101 - Riots
(a) Whoever travels in interstate or foreign commerce or uses any facility of interstate or foreign commerce, including, but not limited to, the mail, telegraph, telephone, radio, or television, with intent—
(1) to incite a riot; or
(2) to organize, promote, encourage, participate in, or carry on a riot; or
(3) to commit any act of violence in furtherance of a riot; or
(4) to aid or abet any person in inciting or participating in or carrying on a riot or committing any act of violence in furtherance of a riot;
and who either during the course of any such travel or use or thereafter performs or attempts to perform any other overt act for any purpose specified in subparagraph (A), (B), (C), or (D) of this paragraph—
Shall be fined under this title, or imprisoned not more than five years, or both.
(b) In any prosecution under this section, proof that a defendant engaged or attempted to engage in one or more of the overt acts described in subparagraph (A), (B), (C), or (D) of paragraph (1) of subsection (a) and (1) has traveled in interstate or foreign commerce, or (2) has use of or used any facility of interstate or foreign commerce, including but not limited to, mail, telegraph, telephone, radio, or television, to communicate with or broadcast to any person or group of persons prior to such overt acts, such travel or use shall be admissible proof to establish that such defendant traveled in or used such facility of interstate or foreign commerce.
(c) A judgment of conviction or acquittal on the merits under the laws of any State shall be a bar to any prosecution hereunder for the same act or acts.
Emphasis added for the words “with intent”.