Presidential jockeying in Iowa has started early, with GOP hopefuls using Republican Joni Ernst’s upstart Senate bid to lay a political foundation for the 2016 caucuses.

Ernst, a state senator and Iraq War combat veteran, has given Democratic Rep. Bruce Braley an unexpectedly competitive fight for retiring Democratic Sen. Tom Harkin’s seat. Her midterm campaign, which could determine the balance of power in the Senate, has coincided with a parade of Republicans making multiple trips to Iowa to position themselves for a nominating contest that is almost a year and a half away.

The prospective Republican presidential candidates arrived in Iowa long before Ernst won her party’s Senate primary in June. But the strong Ernst general election candidacy since then has injected energy and purpose into their budding GOP presidential caucus campaigns. Flipping Harkin’s seat is a priority for Iowa Republicans, and GOP White House aspirants are assisting Ernst as a means to curry favor with activists and expand their networks.

“We want them to come. Anything to help out in 2014 is greatly appreciated,” Iowa Republican operative Chuck Laudner said in an interview. “Our 2016 caucus-goers are already kicking the tires.”

The RealClearPolitics polling average showed the contest deadlocked, and an Ernst victory could signal a successful Election Day for Republicans and go a long way toward the party winning the six seats it needs to assume control of the Senate in 2015. The Republicans eyeing a 2016 presidential bid are aware of the significance, and recent actions and comments by the prospective candidates reflect as much.

Those who have been in Iowa campaigning lately include Sen. Marco Rubio of Florida, Sen. Rand Paul of Kentucky, Louisiana Gov. Bobby Jindal, New Jersey Gov. Chris Christie and Texas Gov. Rick Perry. Christie has visited Iowa to support Gov. Terry Branstad’s easy re-election campaign in his capacity as Republican Governors Association chairman. Of the contenders, only Rubio backed Ernst and invested in her campaign before she won the June 3 primary.

Rubio has plenty of company now. Perry, asked this week during an appearance on "Fox News Sunday" to discuss his travels to Iowa and his plans for 2016, said Ernst was his top priority.

“I hope that I can be very helpful between now and the 4th of November so that Joni Ernst will go to the United States Senate representing Iowa,” Perry said. “Between now to November 4th is what I'm focused on. 2016 will take care of itself.”

Ernst is benefiting from all of the attention, which has come in the form of help with fundraising and drumming up enthusiasm among Iowa Republicans. Presidential contenders tend to draw more television cameras, and attendance at campaign events, than a Senate candidate. Republicans in the Hawkeye State believe that could help Ernst counter what has been a more effective Democratic voter turnout operation.

It also carries some political risk for her.

The Ernst campaign has worked with presidential contenders who are on the ground in Iowa to coordinate messaging where it relates to the Senate contest. But Ernst is campaigning to win over a swing state that twice voted for President Obama. The message she wants to emphasize to a general election audience could occasionally clash with the firebrand rhetoric a Republican White House hopeful might employ to position himself for nominating caucuses often swayed by conservative voters.

Democrats are doing what they can to capitalize. Party operatives in Washington and Iowa believe they can damage Ernst by tying her to the Tea Party generally and Sen. Ted Cruz, R-Texas, and 2008 GOP vice presidential nominee Sarah Palin in particular. Democrats want to force Ernst to answer for their sometimes-risible comments and positions. Cruz is exploring a 2016 bid and has campaigned in Iowa extensively.

In effect, Democrats want to nationalize the race and diminish Ernst’s strength as a more appealing, authentic candidate than Braley.

“Ernst and this parade of presidential wannabes prefer to put ideology before the concerns of Iowa families,” Iowa Democratic Party spokeswoman Christina Freundlich said. “Ernst's flood of national Tea Party support just underscores how wrong her agenda is for Iowa.”

The Braley campaign referred a request for comment to Freundlich.

Iowa Republicans unaffiliated with the Ernst campaign dismissed the Democratic attacks as irrelevant. The Ernst campaign, while quietly acknowledging that the 2016 contenders could cause their candidate some problems, sees mostly upside in the focus it is receiving from them. Media attention for presidential candidates is easy to come by in Iowa, and that has helped Ernst spread her message and counter Braley, Iowa Republicans say.

Next month, former Florida Gov. Jeb Bush is scheduled to headline a Tampa, Fla., fundraiser for a handful of Republican Senate candidates, including Ernst. The campaign said that the spotlight from being associated with Bush and other potential presidential candidates has generally elevated Ernst's profile and increased her ability to raise much-needed resources. Braley closed the second quarter with $2.7 million in cash on hand, while Ernst reported $1.1 million.

Iowa Republican consultant David Kochel, who is advising Ernst, said assistance from GOP presidential contenders has been a “huge” boost to her campaign. “It’s a great way for these 2016’ers to lean in and try and make a real difference."