Moving into the number two spot on our GOP list is Florida Sen. Marco Rubio. The state’s junior senator has enjoyed a solid couple of weeks since announcing his candidacy on April 13, and his new position in our candidate list reflects that. He jumps ahead of Wisconsin Gov. Scott Walker, while ex-Florida Gov. Jeb Bush remains at the top, though it’s important to stress just how tenuous Bush’s slotting remains at this very early point. This trio (Bush, Rubio, Walker) continues to make up our first tier, and they are tightly bunched together.

New survey data reflect Rubio’s improved stature. Prior to his announcement, Rubio had last seen double digits in national GOP primary polling in February 2014. Based on RealClearPolitics’ list of polls, Rubio’s average in the nine 2015 polls taken before April 13 was 5.9%. In the three surveys since his official entry, Rubio averaged 13% and held a (slim) lead in two of them. It’s true that Texas Sen. Ted Cruz got a similar poll bounce after his entry in late March, which seems to have receded somewhat, so it’s entirely possible that Rubio is just the latest benefactor of an announcement bounce.

On the other hand, there’s little question that Rubio is relatively well-regarded by a wide variety of Republicans, from Tea Party stalwarts to establishment types. His potential to receive support from a broad swath of Republicans is one major reason Rubio is a top-tier candidate. In our reaction to Rubio’s entry, we mentioned that Rubio was actually relatively unknown compared to some other GOP contenders, leaving him room to grow as potential voters got to know him. Now that he’s an official candidate, one might say that his poll numbers are catching up to expectations.