Key developments on cultural issues like immigration reform and gay marriage are offering an early preview of potential dividing lines among Republicans considering White House bids in 2016.

In the Senate's vote on comprehensive immigration reform, Sen. Marco Rubio of Florida supported the plan and Rand Paul of Kentucky opposed it.

At the same time, the Supreme Court rulings supporting gay marriage attracted broad criticism from most Republicans considering a presidential campaign. Rubio and New Jersey Gov. Chris Christie said the decisions showed a court overstepping its boundaries. Paul suggested that Republicans need to "agree to disagree on some of these issues."

For Republicans frustrated by President Barack Obama's re-election, the issues offer an early test for a slate of newcomers charting their futures.

[Associated Press]