With just hours to go before the end of the year, presidential campaigns are blasting supporters with emails in an attempt to boost their fundraising totals for the fourth quarter of 2015.

But one Republican presidential campaign is already eagerly promoting its haul.

On Wednesday night, Texas Sen. Ted Cruz's campaign distributed a memo touting a total of $45 million raised over the course of 2015.

That works out to a little less than $20 million in revenue over the last three months, a period where Cruz gained in the polls, won a key endorsement from an influential Iowa power broker and positioned himself as a top-tier candidate in the Iowa caucuses.

"Some campaigns are focused solely on a man, some on a movement. Ours is a hybrid of the two built to win," campaign manager Jeff Roe wrote in the memo, which, on the off chance reporters didn't get the hint of its tone and content, was titled, "We're positioned to win."

Cruz has been strong in the money race previously, with more cash on hand in his campaign war chest — $13.8 million — than any other GOP candidate.

But while Cruz is surging and gaining an increasing amount of attention, his fourth-quarter fundraising total still fell below Ben Carson's $23 million haul over the same three-month window.

The Carson campaign brought in that impressive amount during a period where the outsider candidate dropped several points in the polls. Many observers credit the slowed momentum to the increased focus on national security and foreign policy issues that began following the November terrorist attacks in Paris.

It has yet to be see whether Carson's fundraising trailed off with his poll numbers over the last couple of months. His campaign manager and communications director resigned on Thursday.

Carson has been a strong fundraiser since he entered the race. He raised more than $20 million during the last three-month reporting window, as well. But his campaign has spent a lot of money, so the big question when campaign finance reports are made public at the end of next month will be how much money the campaign still has on hand. A recent Wall Street Journal story reported that while the Carson campaign brought in nearly $9 million in October alone, it spent $9.5 million that month.

While Dec. 31 marks the end of 2015's final three-month reporting period, campaign finance reports won't be made public until Jan. 31, the day before the Iowa caucuses.

Other campaigns aren't yet ready to share their fundraising totals, but several are making major strategic shifts as the calendar turns to 2016, when actual voting begins.

As first reported in the Des Moines Register, former Florida Gov. Jeb Bush's campaign is shifting its resources, scaling back advertising campaigns in early-primary states like Iowa and shifting resources to staffing on the ground to work on boosting voter turnout.

Bush's behemoth superPAC, Right To Rise, has been doing the bulk of ad spending on his behalf and will continue spending millions on TV in early states.

And while Bush's campaign is canceling ads, front-runner Donald Trump is preparing to hit the TV airwaves for the first time. Despite spending much of 2015 ahead in the polls, Trump has spent hardly any money on what's typically a staple of a presidential campaign.

His campaign has run only about $200,000 worth of radio advertising. During the last reporting period, Trump spent more money printing T-shirts than he did advertising his candidacy. That's not surprising, given the amount of free media he generally receives.

Now, though, Trump says he is ready to spend $2 million a week on ads in early-primary states. "Now I'm going to be spending," Trump said in South Carolina Wednesday. "You probably saw I'm going to spend now — going to start spending a lot of money because I don't want to take any chances."

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