From a DSCC email:

Dear Greg,
It is sickening. But not surprising.
Today’s Republican Party is so depraved that they’re running ads in Florida trying to connect a Democratic candidate to 9/11 attacker Mohammed Atta. They’re in North Carolina attacking Democratic Senate candidate Kay Hagan’s faith and character. And in Colorado, Democratic Senate candidate Mark Udall is the target of a GOP robocall campaign making the insane accusation that he supports human cloning.

I assume Kerry means the Tom Feeney (R) vs. Suzanne Kosmas (D) race and the Feeney ad alleging Kosmas’ support of drivers’ licenses for illegal immigrants.

As for the Hagan/Dole race, Kerry’s is referring to this ad:

Since August, before the event took place, Dole’s campaign has been calling attention to a Sept. 15 fundraiser that Hagan planned to attend in Boston with author Wendy Kaminer and her husband, Woody Kaplan. He was was on the advisory board of the Godless Americans political action committee and active in a group that promoted “secular” ideas.
The ad featuring Hagan airs a comment from one the organization’s leaders saying “There was no Jesus.”
The announcer says “A leader of the Godless Americans PAC recently held a secret fundraiser in Kay Hagan’s honor.”
“Godless Americans and Kay Hagan. She hid from cameras. Took godless money. What did Hagan promise in return?”

Hard hitting, but both seem legit to me.

How about the “insane” attacks on Udall and cloning in Colorado? From OnTheIssues.org on Udall’s voting record regarding cloning:

Voted NO on forbidding human cloning for reproduction & medical research.
Vote to pass a bill that would forbid human cloning and punish violators with up to 10 years in prison and fines of at least $1 million. The bill would ban human cloning, and any attempts at human cloning, for both reproductive purposes and medical research. Also forbidden is the importing of cloned embryos or products made from them.
Reference: Human Cloning Prohibition Act; Bill HR 534 ; vote number 2003-39 on Feb 27, 2003