Paul told CNN over the weekend that his speech is not intended to be “divisive,” but is simply an “extra response.” Appearing on “State of the Union with Candy Crowley,” he said that while he might emphasize some things that “maybe Marco doesn’t” (he cited foreign aid as one example), he wasn’t planning to use the occasion to highlight intra-party disagreements: “I won’t say anything on there that necessarily is like, ‘Marco Rubio is wrong.'”

But there’s clearly an emerging rivalry between the two men – both considered likely 2016 presidential candidates – that reflects the larger split within the Republican Party. Paul himself seemed to unintentionally acknowledge this when he added: “I don’t always agree [with Rubio], but the thing is, this isn’t about he and I [sic], this is about the tea party.” …

By contrast, Paul is emerging as 2016’s most intriguing dark-horse contender. In many ways, he’s the inheritor of the independent, outside-the-box mantle of his libertarian father, former GOP Rep. and presidential candidate Ron Paul. But he’s also trying to position himself as a more traditionally conservative, tea party candidate in the mold of, say, Representative Bachmann. As someone who clearly isn’t taking marching orders from the GOP establishment, Paul could present a real challenge to the eventual party frontrunner – whether Rubio or someone else – and push the entire field to the right.