3:27 p.m. update: Perry announced Monday afternoon that he will not seek reelection, saying, “The time has come to pass on the mantle of leadership." As for what's next, Perry said: “Any future considerations I will announce in due time, and I will arrive at that decision appropriately."

It's decision day for Texas Gov. Rick Perry (R).

The longest-serving governor in Texas history will announce "exciting new plans." That basically means he will either announce that he is running for a fourth full term in 2014 or he is not.

While Perry has been an unpredictable politician throughout his career, the smart money is on him passing on another bid with an eye on something bigger.

Here's why.

Perry clearly has his sights on something above and beyond the Texas governor's mansion. How do we know this? In short, 2012. Perry ran for president after initially saying he was not interested. And now, he has not shut the door on a 2016 run, despite a much-hyped campaign that fizzled badly.

Bill Miller, a Republican strategist and lobbyist who has known Perry for a long time, is convinced he won't run for reelection. Miller's sense is that Perry has his eye on a return to the national political arena.

"I'm 100 percent that he's not running for reelection, but that's not because he has told me that," said Miller, who said he recently spoke with Perry.

Rice University political scientist Mark Jones took the same view, saying in an interview that "at this point all the signals are that he is not running for governor."

Perry is 63, and the reality is that he's at or near the end of his political career. Another run for governor would hardly be the best way to prepare for a 2016 presidential bid. Perry would be occupied with a state race all the way until November 2014 -- the point at which many 2016 candidates will already be prepping, or at least thinking about, a rollout for some time in 2016.

Plus, there is already a Republican waiting in the wings to fill Perry's shoes with whom the governor shares a close relationship. That Republican is Attorney General Greg Abbott (R). He's been raising big bucks as he's geared up for a gubernatorial bid and would be a major front-runner in an open race. Perry would be hard-pressed to find a better exit scenario in which he can pass the baton to a political ally. Abbott, it's worth noting, wouldn't run against Perry, according to the governor.

“I think tomorrow afternoon [we] will be more than happy to discuss what his future plans would be and/or mine,” Perry said on "Fox News Sunday" when asked about Abbott. The governor shed no new light on his upcoming announcement in the interview, and his advisers have been tight-lipped.

"The Abbott machine has been growing by leaps and bounds," noted Jones.

Perry's 2012 presidential campaign got off to a late start. By opting not to run for another term as governor, Perry would free himself up to get an earlier start this time. He could get things rolling well in advance of 2016 by traveling through the early nominating states like Iowa and South Carolina, where appealing to social conservatives would be Perry's best chance to upset what promises to be an imposing slate of GOP contenders.

"If you think about his prospects as a candidate, he's got to do well early," Miller said.

It would be somewhat surprising to see Perry announce a full presidential campaign Monday. It's very, very early to do such a thing. But announcing a broad new political goal or focus that may one day lead to one doesn't seem far-fetched.

Something along the lines of a "wink, wink, nod, nod" announcement would not be surprising, said Jones.

Perry has reinforced his support on the right by emerging as the face of a high-profile fight over abortion laws in Texas. And as abortion has emerged as a contentious political issue on the national radar, Perry's tough stance in Texas gives him a natural way into the larger political conversation.

All that said, Perry, to repeat, is very hard to predict. So, while for all of the reasons outlined above, a reelection campaign would seem like a surprise, we've come to expect the unexpected when it comes to the Lone Star State governor. And if he does decide to run for another term, he'd start as a heavy favorite to win.

"I suppose you need to be there in San Antonio tomorrow and find out with everyone else," Perry said on "Fox News Sunday" when pressed about his decision.

No matter what Perry decides, he's certainly proven that he has a flair for the dramatic.