Republican candidates aiming to generate national buzz to help win a seat in Congress need to launch their campaigns soon or risk being drowned out by the looming presidential campaign, according to GOP strategists.

Several young, upstart candidates last cycle were able to tap into the energy and resources of the Tea Party and conservative movements by getting in the race early, building a national profile and raising money online.

In some cases, as with newly elected Sen. Marco RubioMarco Antonio RubioLobbying world Former Florida congressmen mull bipartisan gubernatorial run: report Winners and losers from Jim Bridenstine’s confirmation as NASA administrator MORE (R-Fla.), they were able to defeat more established candidates.

“If you want to emerge as quote, unquote, ‘the Marco Rubio of 2012,’ you’ve only a short window to communicate a message to a national audience before the presidential race sucks all the life out of the room,” said Kurt Luidhardt, an Indiana-based GOP consultant who specializes in Internet outreach and fundraising.

Chip Saltsman, a Tennessee-based Republican consultant, echoed that advice, but warned candidates that they have more to worry about than the presidential primary.

“Get in front of them early,” he said. “Because there’s a lot of hungry mouths on the House side and a reenergized [Republican National Committee]. It’s going to be competitive.”

None of the leading contenders for the Republican White House nomination have declared their candidacy, but they’re expected to reveal their plans in the coming weeks. Some GOP Senate candidates, meanwhile, have declared their intention to run.

In Missouri for instance, former state Treasurer Sarah Steelman declared her intention to challenge Democratic Sen. Claire McCaskillClaire Conner McCaskillOvernight Cybersecurity: Homeland Security official says Russia likely targeted more than 21 states | Senate approves Trump's NSA chief | Lawmakers unveil bipartisan internet privacy bill Senators debate new business deduction, debt in tax law hearing Russia likely targeted more than 21 states before 2016 election: official MORE in December – more than a year ahead of the primary vote.

Long-shot candidates and those running without party backing will have to look beyond tradition sources of support in order to be successful, said Luidhardt.

“People who might traditionally be considered long-shot candidates, particularly folks who aren’t getting the $2,400 contributions as easily as others, they’re going to have to fund their campaign online,” he said. “If you’re going to raise national money, you've got to run a national campaign. If you’re going to do that, you’ve got to start now.”

In 2012, Rubio was one of several candidates who became stars in the conservative and Tea Party movements. But he was initially the underdog in the Florida Republican primary, when then-Gov. Charlie Crist was the favorite.

“He lagged behind in fundraising very early,” said Saltsman, who ran then-Arkansas Gov. Mike Huckabee's 2008 presidential campaign. “People were saying, ‘he needs to get out because he doesn’t have the money.’”

There’s risk to getting in early, added Saltsman. “People can lose some enthusiasm. And once you get started, you start spending money. You have to be very disciplined.”

Todd Harris, a strategist for Rubio's campaign, said that when the 39-year-old Republican began campaigning in early 2009 "it wasn't even a contest ... in the minds of most observers." And that made it difficult to raise money locally.

"Because the Florida press had already written us off, we actually looked outside of Florida first, to build a base of support among activists, small dollar donors, and the conservative press, and then used that support to boomerang back into Florida," Harris said in an e-mail.

Rubio’s fundraising picked up steadily and he went on to rake in some $20 million for his campaign. He ended up getting the backing of the party and Crist dropped out of the primary to run in the general election as an Independent.

"We benefited from the fact that Crist and his campaign arrogantly dismissed us even as we were climbing in the polls. By the time we overtook him, it was too late," said Harris. "They attacked us on TV but by that time we already had such a strong base of support, after more than a year of cultivation, that their attacks had no credibility and no impact."