Presidential contender Marco Rubio is flooding the zone with endorsements and grassroots coalitions after keeping their existence under wraps for months.

In crucial Iowa, the Republican senator from Florida locked up chairmen for all 99 counties three months ago; per standard practice for his campaign, he declined to broadcast it. But that has begun to change. During the first week of 2016 alone, Rubio announced the existence of more than half-dozen grassroots, finance coalitions and high profile conservatives that are supporting his campaign. In the next few days, Rubio plans to unveil a list of campaign chairmen that are in place in all 50 states.

"Our campaign is about Marco and his message," Rubio campaign spokesman Alex Conant said. "Having endorsements and grassroots supporters helps us get his message to even more people. Now is when it matters."

Rubio is locked in a volatile brawl for the GOP presidential nomination.

What appeared to some political observers in the waning days of last year as a lack of a grassroots network led to questions about the strength of his campaign. Rivals eagerly spread the news about their growing networks of supporters and foot soldiers, particularly the grassroots-focused Ted Cruz; Rubio kept quiet. It was a part of his concerted strategy to avoid peaking in the polls too soon. The plan has always been to make a splash this month, just as voters begin to pay more attention and solidify their choices.

Already, a few candidates have mistimed their rise, including Wisconsin Gov. Scott Walker, who has since dropped out of the race, and retired pediatric neurosurgeon Ben Carson, who led state and national polls in October before sagging back toward the bottom of the field.

"They don't want to raise expectations too soon," a Rubio supporter said.

With first votes less than a month a way, the Rubio campaign is shifting gears and following through with plans to use January to highlight the senator's support and expanding network. On Friday alone, the senator dropped press releases publicizing an "expanded" leadership team in North Carolina; the support of Iowa agriculture leaders and the backing of more than 150 grassroots leaders in South Carolina.

Earlier in the week, Rubio unveiled his North Carolina legislative team; South Carolina finance chairs; a religious liberty advisory board that includes some well-known figures; a Texas leadership team; the endorsement of Chris Chocola, former president of the conservative activist group Club for Growth; and county leaders for northwest Iowa, the most conservative part of the state.

Most of Rubio's rivals charted a different strategic path, notably Cruz, the Texas senator who is leading in Iowa and places second in most national polls, and former Florida Gov. Jeb Bush, who has been stuck in the middle of the pack for months. Both candidates have built vast grassroots networks in the early primary states and those that will vote in March and April, and both have made sure that each supporter and coalition was announced as they signed on or were formalized.

The value in that, said a Republican strategist who prefers the Bush/Cruz approach, is that every piece of news about the growth of a candidate's grassroots network can make a positive impression with other political activists, encouraging them to join what appears to be a strong and growing campaign. The GOP strategist said Rubio's approach is more advantageous from a communications and media perspective, but less effective from an organizing standpoint.

This strategist, who was sympathetic to Rubio's strategic concern about peaking too soon and requested anonymity so as not to criticize him publicly, likened the primary campaign to a football game. "Nobody says, lets stay behind until the fourth quarter," this Republican said. "I have never had an election where I wanted to be behind on any day."

Rubio is currently running third in the RealClearPolitics average of national GOP primary polls; third in Iowa; and second in New Hampshire. The voting begins Feb. 1 with the Iowa caucuses, followed by the New Hampshire primary on Feb. 9 and the South Carolina primary on Feb. 20.