While Republicans look over names of possible Al Franken challengers, the first-term Democratic U.S. senator is laying groundwork for his 2014 re-election run.

And he is using more humor than we heard when he first ran four years ago.

In a fund-raising email, Franken claimed to have hired a Republican fact-checker to help his campaign. Franken added comments to an email “Scott” supposedly wrote. Excerpts:

Scott: He must raise $14 billion by the end of September.

Franken: We actually only need to raise $25,000. But I guess I like the ambition? (You can help by clicking here and making a contribution of $10 or more right now.) I had to change the link; it originally led to a video of a baby sloth eating a banana, which I’ll admit I watched for a while because it was pretty adorable.

Scott: If we hit the fundraising goal this month, Al gets to decide the Senate’s lunch menu for a whole week!

Franken: Really? That doesn’t sound right. But, hey, let’s find out (click here to help reach our September fundraising goal!).

Franken avoided over-doing the comedy bit during the 2008 campaign and early in his tenure, apparently not wanting to overemphasize his time as a comedy writer and comedian, including on “Saturday Night Live.”

He has avoided comedy so much that fellow Minnesota U.S. Sen. Amy Klobuchar, a lawyer, has garnered more comments for jokes than Franken.