Published: Jul 31, 2013 6:00 AM EDT

WASHINGTON (AP) - The Senate is ready for a showdown vote on President Barack Obama's choice to head the Bureau of Alcohol, Firearms, Tobacco and Explosives.
    
Wednesday's roll call will carry echoes of this year's battle over gun control. Obama and his allies lost that fight, which followed last December's massacre of 20 schoolchildren and six faculty members at an elementary school in Newtown, Conn.
    
This time, the focus is on B. Todd Jones, whom Obama wants to lead the ATF. That agency helps enforce federal gun laws.
    
When Obama nominated Jones in January, he seemed unlikely to prevail. His chances were enhanced this week when the powerful National Rifle Association said it would be neutral on his nomination.
    
Samantha Power is expected to win Senate approval to become United Nations ambassador.