Turns out Robin Carnahan and Barack Obama have more in common than just party affiliation.

Today is the president's birthday -- as well as Carnahan's. Not only were they born on the same day, they were born on the same exact day -- August 4, 1961.

Both Obama and Carnahan, who secured the Democratic nomination for U.S. Senate last night, turn 49 today. To mark the occasion, Robin's mother Jean, a former U.S. Senator herself, sent Robin's supporters an email asking for a donation of $49.

Republicans, of course, had a different approach.

Lest they miss a chance to link the president's sagging poll numbers with their competition in November, the Missouri GOP used the shared birthday as a hook for a new release seeking to tie the two together on policy issues as well.

The icing on the cake was an actual cake: The GOP had a festive dessert delivered to Carnahan's campaign office in Clayton today.

"Happy Birthday Barack Obama and Robin Carnahan," the blue icing says.

Wonder if the Carnahan campaign will list the offering as an "in-kind" donation -- even if wasn't meant to be kind.