(CNN) It's become as much a campaign ritual as chowing down on fat-laden food on a stick and working the rope line at rallies: the pilgrimage by White House hopefuls to the Holy Land.

Serious presidential candidates, especially Republicans, now routinely extend the campaign trail to Israel to vow solidarity to the Jewish state, bolster their foreign policy credentials and impress pro-Israel donors and evangelical voters back home. Former Arkansas Gov. Mike Huckabee, who Tuesday started a trip to the country, is only the latest in a long line.

The trips allow the candidates to look like statesmen abroad and -- nowadays -- draw contrasts with President Barack Obama and his estranged relationship with Prime Minister Benjamin Netanyahu. But are the hassles, expense and time off the trail really worth it for the candidates?

Hillary Clinton launched her presidential bid on April 12 through a video message on social media. The former first lady, senator and secretary of state is considered the front-runner among possible Democratic candidates."Everyday Americans need a champion, and I want to be that champion -- so you can do more than just get by -- you can get ahead. And stay ahead," she said in her announcement video. "Because when families are strong, America is strong. So I'm hitting the road to earn your vote, because it's your time. And I hope you'll join me on this journey."

Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid. "I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University.

Ohio Gov. John Kasich joined the Republican field July 21 as he formally announced his White House bid. "I am here to ask you for your prayers, for your support ... because I have decided to run for president of the United States," Kasich told his kickoff rally at the Ohio State University.

Sen. Ted Cruz of Texas has made a name for himself in the Senate, solidifying his brand as a conservative firebrand willing to take on the GOP's establishment. He announced he was seeking the Republican presidential nomination in a speech on March 23."These are all of our stories," Cruz told the audience at Liberty University in Virginia. "These are who we are as Americans. And yet for so many Americans, the promise of America seems more and more distant."

Businessman Donald Trump announced June 16 at his Trump Tower in New York City that he is seeking the Republican presidential nomination. This ends more than two decades of flirting with the idea of running for the White House."So, ladies and gentlemen, I am officially running for president of the United States, and we are going to make our country great again," Trump told the crowd at his announcement.

Fred Zeidman, a businessman and board member of the Republican Jewish Coalition, which often helps facilitate visits of high-profile Republicans, said that it was smart for presidential candidates to go to Israel to brief themselves on a region that he said provides the single biggest threat to the United States.

"It is a genuine need on their part to truly understand not only the issues that are facing Israel, but the issues that are facing the U.S. You have got to have an understanding of them," said Zeidman, adding that those who argue the trips served merely as a political stage are wrong.

"You gain more by eating a corn dog in Iowa for three days than by going to Israel," Zeidman said, referring to the domestic political payoff to a campaign for visiting Jerusalem.

But politics often seem to be at the forefront of many visits.

The former Arkansas governor actively used his visit to Israel as a political platform, telling CNN in an interview that the Iran deal that Obama says will stop the Islamic Republic from obtaining a nuclear weapon was a capitulation and would actually lead to an Iranian bomb.

"We caved on all of it," Huckabee said on "The Situation Room" with Wolf Blitzer.

And in the highly polarized environment whipped up by the open feud between Netanyahu and Obama amidst the fallout over the nuclear deal, the trips by Republican candidates have become even more politically explosive.

Huckabee's visit comes just a few weeks after he charged in an interview with Breibart News that by agreeing to the deal, Obama was marching Israel to the "door of the oven," using stark Holocaust imagery to condemn the agreement.

But RJC spokesman Mark McNulty said that the trips have an important educational component. Candidates, especially those with scant experience of international diplomacy, are often taken aback by Israel's physical geography, which gives them new appreciation for the risks it faces.

"When you get there and you are able to drive or fly from one side to the next -- it gives you a real factual and instinctual feeling for how small it is and how precarious a position it is in as a country," McNulty said.

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Former President George W. Bush experienced such an epiphany during his first visit to Israel in 1998, when he was taken on a helicopter ride over Israel by Ariel Sharon, then an Israeli minister and prime minister during Bush's term.

The episode hinted at a delayed diplomatic value for trips to Israel by White House hopefuls who later become president.

"He knew every inch of the land and it didn't seem like he intended to give any of it back," Bush wrote in his memoir "Decision Points" of Sharon.

"I was struck by Israel's vulnerability in a hostile neighborhood," continued Bush, who went on to become one of the most pro-Israel U.S. presidents in modern history.

In addition to such helicopter tours showcasing Israel's perilous geographic perch, candidates usually sit down with Israeli prime ministers and opposition leaders, scout areas in the firing line for Hamas rockets and visit the iconic ancient religious sites.

In addition to Huckabee, Wisconsin Gov. Scott Walker, a foreign policy neophyte, visited Israel in May -- riding in a helicopter close to borders with Lebanon and Syria.

Walker said that the trip, during which he met Netanyahu and Israeli opposition leader Isaac Herzog, made a deep impression on him and, though he supported a two-state solution for the Israeli-Palestinian question, the Middle East was "not ready" for that right now.

Trying to woo campaign donors

Walker rival Marco Rubio was in Israel as part of Middle Eastern tour in 2013, a year when fellow Republican candidates Rick Perry and Rand Paul also visited. The only woman in the GOP field, Carly Fiorina, frequently name drops about her friendship with "Bibi Netanyahu" and Jeb Bush, the former Florida governor, has visited Israel multiple times.

Candidates often earn more than just an enhanced geopolitical perspective. Critics of Republicans see them as means to rack up points -- and dollars -- from pro-Israel and Jewish donors.

"People are going to Israel not on fact-finding missions, not to make themselves smarter on foreign policy, they are going to Israel to show to some very, very large donors they can pass their litmus tests for hawkish views on Israel," said Matt Dorf, who formerly worked as a liaison to the Jewish community at the Democratic National Committee.

When 2012 Republican presidential candidate Mitt Romney visited, he held a fundraiser where seats cost five figures.

Israel's security is a preoccupation of a number of big donors who fund super PAC committees able to spend vast sums to support candidates.

"There is clearly a Sheldon Adelson primary," said Daniel Kalik, vice president of political affairs at J Street, a progressive pro-Israel advocacy group in Washington, referring to the casino magnate who has spent millions of dollars supporting Republican politicians.

But it's not only Jewish heavyweights like Adelson who progressive activists see as the target for Republicans' visits.

"Someone like Huckabee is also doing it for conservative primary voters," said Dorf, referring to Christian conservatives who revere the land of Israel for religious reasons and who play a significant role in nominating contests in early states like Iowa and South Carolina.

GOP candidates rarely meet with Palestinians

But it's not only Republican candidates who travel to Israel. In 2008, Obama stopped there as part of a European and Middle Eastern tour, meeting top political leaders including then-Prime Minister Ehud Olmert and then-President Shimon Peres.

He also visited with Netanyahu, then the Likud Party leader who headed the Israeli opposition -- the opening gambit in a political relationship that would develop into a bitter estrangement over Iran and the peace process and severely test U.S.-Israel ties.

Unlike many Republicans, Obama also traveled to the Palestinian administrative center in Ramallah in the West Bank, laying the groundwork for what would be several intense but futile attempts to solve the Palestinian question during his presidency.

The fact that Republican candidates rarely meet Palestinian politicians is in part a sign that they tend to side more closely with Israelis in the right-wing Likud Party of Netanyahu.

But it's also a sign that with the fractured peace process, their cause has become less prominent in the United States and throughout the wider Middle East, which is wracked with sectarian conflict, said Hussein Ibish, senior scholar at the Arab Gulf States Institute in Washington.

"Nobody cares about them, because there is no peace process," Ibish said.

It remains unclear whether any Democratic candidates will visit Israel during this campaign. The favorite for the nomination, Hillary Clinton, would not need a visit to familiarize herself with the place, having served as secretary of state and dealt with Israeli leaders dating back to her husband's administration.

And Clinton, like other Democratic candidates, already has a strong standing with Jewish voters, who tend to be socially liberal and side overwhelmingly with the Democratic Party in general elections.

Republicans are aware of this, and Zeidman said they hold few illusions about winning over the constituency by taking pictures of themselves at the Western Wall.

"They are unequivocally not going because they think they are going to woo the Jewish vote," said Zeidman.