ANALYSIS: Rubio and Paul preview possible 2016 showdown in State of the Union responses

When President Barack Obama finishes his State of the Union address Tuesday night, Florida Republican Sen. Marco Rubio will deliver the official GOP response. Then Kentucky Republican Sen. Rand Paul will give the “tea party response.”

It probably won’t be the last time these two potential 2016 presidential candidates compete on the national stage.

Rubio and Paul were elected to the U.S. Senate under similar circumstances in 2010. In their primary races, they both faced opposition from state and national party leaders while enjoying the support of tea party groups and then-South Carolina Republican Sen. Jim DeMint.

Paul easily beat Kentucky Secretary of State Trey Grayson, Senate Minority Leader Mitch McConnell’s preferred candidate. Rubio drove his primary opponent, Florida Gov. Charlie Crist, out of the Republican Party.

Since taking office, both senators have courted conservatives. Heritage Action ranked Rubio and Paul among their top six conservative senators, with each of them earning 96 percent on the group’s congressional scorecard.

The two men have also cooperated on policy issues. Rubio was one of only 19 senators to back Paul’s proposal to block the sale of fighter jets and tanks to Egypt. They were among a handful of Senate Republicans to vote against the bipartisan fiscal cliff deal in the waning hours of the 112nd Congress.

But they have also given diametrically opposed foreign policy speeches, with Rubio decrying isolationism within the GOP in a talk at the Brookings Institution while Paul went to the Heritage Foundation to tie realism to Ronald Reagan.