Watching the fight unfold between President Barack Obama and Senate Republicans over who should choose the next Supreme Court justice, Michael A. Bowden got angry at what he saw at the latest affront to the first black president.

And then his thoughts turned from Washington to his own state.

Obama won't be on the ballot this fall, but Pennsylvania GOP Sen. Pat Toomey will — and Bowden has made defeating him in November a priority.

"This kind of thing really burns me to the core," said Bowden, a 56-year-old Air Force veteran from Philadelphia. "I've already started planting the seed in people's heads that Sen. Toomey is one of those people in lockstep with the Republicans. This could give him a wake-up call that he could be vulnerable as well."

Democrats are pressuring senators in Pennsylvania, Ohio, New Hampshire, Illinois and Wisconsin to back down from their refusal to confirm or even consider Obama's nominee to succeed the late Antonin Scalia or face the consequences in November. In some states, they may get help from African-Americans who see the court battle as the latest GOP snub of Obama — one rooted in racism, which could galvanize a crucial component of the Democratic voting bloc.

"The Obama presidency has been mobilizing for African-Americans," said Daniel Hopkins, a professor at the University of Pennsylvania whose research focuses on racial and ethnic American politics. "The Supreme Court nomination is part of a much broader story of deeply polarized and sometimes racialized hostility between Obama and his political opponents. It's potentially quite a potent issue in a state that has backed Obama twice."

Many African-Americans trace what they see as similar insults back to Obama's historic election in 2008, when questions were raised about his U.S. citizenship and family in Kenya. In the days after Scalia's Feb. 13 death, Republicans quickly signaled their opposition to Obama nominating a successor, saying they would refuse to hold hearings on a nominee and calling for the conservative justice's replacement to be chosen by the next president.