From the article:
“REP. ROBERT WEXLER, (D) FLORIDA: And if he refuses to honor the subpoena, then the full House of Representatives must hold Mr. Rove in contempt of Congress..."
What he hasn't done is agree to voluntarily talk with the House Judiciary Committee about the prosecution of Alabama‘s former Democratic governor. What they are jacked up about is his refusal to honor a subpoena except that he has not been subpoenaed so he can not have refused to honor it and he (so far as I know) has not said he would refuse to honor one if it was issued. They are hysterical over something they imagine he might do.
At least one of Rove’s problems is the deal Scooter Libby got. As you may recall, Scooter made an alleged mistake in his testimony and got prosecuted for perjury or obstruction or something like that. I would not blame Rove or anyone for taking the Fifth because even if you tell the truth under oath you can have incriminated yourself if enough others swear to something different.