This is pretty brazen. Since the solicitation was made on a radio show and it was taped, it can't be denied. From 'Illegal plea for illegals' cash?':

As Rep. Chris Cannon sat by, one of his aides urged any illegal aliens listening to a Spanish-language radio talk show to funnel money into his campaign by giving it to U.S. citizens who could donate it legally.

However, federal law not only bans political donations from foreign nationals, it also bans such funneling through citizens, too - and the solicitation or receipt of it.

Still, Marco Diaz, an aide to Cannon, R-Utah, told Radio Unica in Spanish on May 22, "If you are undocumented you must find, we welcome this money, but you have to find someone who is legal in order to donate money."

A couple other ways to get Cannon his money were discussed on the show, such as through the U.S. citizen children of illegal aliens.

The 6/14/04 entry here has quotes from both the show and the Federal election laws.

Previous Cannon coverage starts here.