Because the answer is no.

Via Politico:

The chairman of the House Democrats’ campaign arm is staying mum on which of his party’s candidates want to campaign with President Barack Obama.

“Every Democrat makes their own choices and their own decisions,” Democratic Congressional Campaign Committee Chairman Steve Israel told reporters Wednesday.

Pressed again, the New York congressman responded: “I have not had any conversations with any candidates about campaigning or not campaigning with President Obama. Those decisions are best left with individual candidates and members.”

Obama’s poor standing in the polls has added to Republicans’ hopes of making gains in this year’s midterm elections. Israel, however, highlighted numbers that he said showed peril for the GOP.