(CNN) - Sen. Claire McCaskill says she's supporting an independent political action committee that's urging Hillary Clinton to run for president in 2016.
"Hillary Clinton had to give up her political operation while she was making us proud, representing us around the world as an incredible secretary of state, and that's why Ready for Hillary is so critical," said McCaskill, in a statement put out by the political action committee.
"It's important that we start early, building a grassroots army from the ground up, and effectively using the tools of the Internet – all things that President Obama did so successfully – so that if Hillary does decide to run, we'll be ready to help her win," added McCaskill.
The move by McCaskill should not be seen as a surprise, as she's become a strong supporter of Clinton. In a statement in February, when Clinton stepped down as secretary of state, McCaskill said "I know that Hillary will succeed in whatever comes next for her – and if her future plans include seeking the presidency, which I hope they do, then I look forward to being on her team and working my heart out to see her elected."
But McCaskill once had a rocky relationship with Hillary and Bill Clinton. She was an early supporter of then-Sen. Barack Obama's 2008 campaign for president. The one-time longshot senator from Illinois eventually upset Clinton for the Democratic presidential nomination in a historic and marathon primary battle that lasted until June of that year.
Even though the next race for the White House is a long way away, there's already intense speculation over whether the former first lady and senator from New York will make a second bid for president.
When asked just before she stepped down as secretary of state whether she was thinking of making another run for the White House, Clinton said "I am not thinking about anything like that right now."
And in an interview with CNN later that day, when asked if she's decided against another candidacy for president, Clinton responded that "I have absolutely no plans to run." But she added that "I am lucky because I've been very healthy. I feel great. I've got enormous amounts of energy that have to be harnessed and focused, so I'm very fortunate. I'm looking forward to this next chapter in my life, whatever it is."
And the profile on her new Twitter account, which was unveiled earlier this month, listed her future as "TBD," which only fueled speculation she's not finished with presidential politics.
If she does run for the White House, Clinton would instantly become the overwhelming front runner for the Democratic nomination.