Senator Dan Coats, who came out of retirement to take back Indiana’s Senate seat from Democrats in 2010, has decided to hang it up after one term in his comeback. Citing his age and his desire to spend time with his family, Coats announced his retirement in a homemade video — one that opted out of the laughable artifice of Barbara Boxer’s announcement:

“Today I am announcing that I will not seek re-election to the United States Senate,” Coats said in a statement. “This was not an easy decision. While I believe I am well-positioned to run a successful campaign for another six-year term, I have concluded that the time has come to pass this demanding job to the next generation of leaders.”

WRTV, the local ABC affiliate in Indianapolis, broke the news earlier today:

What happens now? Coats’ decision may have surprised some, but his reference to a solid Republican bench is hardly unwarranted. The GOP will have a number of options, including one of Coats’ closest aides, Eric Holcomb:

Coats’s decision to retire may set off a Republican scramble for the open seat. While the GOP would seem to have the early edge, it is now another state they must defend in a presidential year where they’re almost entirely playing defense to protect their new Senate majority.

Potential Republican candidates include Reps. Todd Young and Susan Brooks, both of whom have long been viewed as having statewide ambitions, as well as Indianapolis Mayor Greg Ballard and Reps. Todd Rokita, Jackie Walorski and Marlin Stutzman. …

“Eric has taken a leave of absence from Senator Coats’ office as he considers a run for the open U.S. Senate seat in 2016. He’s grateful for the immediate outpouring of support from every corner of Indiana and will make a decision soon,” Pete Seat, a spokesperson for Eric Holcomb, said in a statement.

It’s still a Republican seat to lose, but one person might have the resources to flip the seat back to the Democratic Party. And that may be the man who retired and gave Coats his opening in 2010:

And the competitiveness of that race relies in large part on one number: $9.9 million.

That’s the ungodly sum of money that retired Sen. Evan Bayh (D-Ind.) has just sitting in his campaign account. Bayh succeeded Coats when Coats retired in 1998, and Bayh returned the favor by retiring and making way for Coats in 2010. In both cases, there was a sense that the retirements weren’t entirely voluntary, but rather were about the difficulty of the campaign ahead. (Bayh was a popular recent former governor in 1998; by 2010, he had to answer for his vote on things like Obamacare in an increasingly red state and a bad year.)

Bayh has certainly left his options open. While he has said he won’t run for governor in 2016, he hasn’t ruled out a return to politics. And that $9.9 million war chest is so big that most incumbent senators would be overjoyed to have it. Combine it with Bayh’s moderate reputation, and it’s little secret how happy the Democratic establishment would be to have him in the race.

The question is whether Bayh kept that money in the bank for just such an occasion. The former senator and governor, after all, is a relatively young 59. And while he has been talked up as a potential presidential candidate or VP pick in the past, that ship has largely sailed, it would seem. So the money largely has one place to go: Another run for Senate.

Or perhaps a run at the Presidency now, with Hillary Clinton under fire from the media, and under pressure from progressives to go further Left. A Bayh run could keep Hillary tracking back toward the center in the primary. But yes, if Bayh sits out the presidential sweepstakes, then Democrats will put considerable pressure on him to use the money on his own comeback to the US Senate. That would still force Bayh to explain his ObamaCare vote, among others that propped up an increasingly unpopular Barack Obama, but $9 million buys a lot of time for explanations and evasions.