Obama enlists Biden to lobby Senate GOP on gun control Vice President Joe Biden UPI/Dennis Brack/Pool WASHINGTON, April 1 (UPI) -- U.S. Vice President Joe Biden has undertaken an intense lobbying effort to get Republican senators to support gun control, officials said. Biden has already met personally with several senators, including Lindsey Graham, R-S.C., John McCain, R-Ariz., and Johnny Isakson, R-Ga., in an attempt to sway the GOP senators to support measures such as universal background checks and outlawing large capacity ammunition clips. The Hill said Monday President Barack Obama has enlisted Biden, who has proven a top administration surrogate among his former colleagues in the Senate, to help assure passage of a gun control law in the wake of December's school shooting in Newtown, Conn. How effective Biden has been remains to be seen. None of the senators who've met with the vice president have indicated support for the measure. "His effectiveness depends on how you define his role," said GOP strategist Ken Lundberg. So far, his work has been to rally allies and berate opponents. In that role, he's very effective but, as for reaching out to the other side, he's impotent. He's breaking no new ground ... .