(Reuters) - After a long and sometimes arduous courtship, soccer has finally revealed its charms to Americans who have embraced the World Cup in record numbers.

With the United States through to the knockout phase and interest and television ratings soaring, soccer can rightfully claim a place at the American sporting table.

Alongside the National Football League, Major League Baseball, National Basketball Association and National Hockey League, it has changed North America's Big Four into the Fab Five.

Often seen as the outsider looking in, a niche sport craving mainstream status, soccer has muscled its way into the day-to-day sporting discussion as an engrossing tournament in Brazil pulls in more-and-more soccer converts by the day.

A record 25 million viewers tuned into watch the U.S. take on Portugal in the group stage and with the Americans preparing to face Belgium on Tuesday for a place in the quarter-finals, that mark is almost certain to be smashed.

But not all Americans have joined the World Cup party.

While President Barack Obama was pictured leading the cheers from Air Force One, conservative political commentator Ann Coulter was warning that "any growing interest in soccer can only be a sign of the nation's moral decay".

Coulter's spin on the beautiful game generated predictable outrage, a few laughs and a brief social media firestorm. But it is clear that American appetite for all things soccer is growing.

On the pitch, the U.S. men have qualified for seven consecutive World Cups while the women are the world's top ranked team.

At the grassroots level soccer has always been popular in the United States with close to four million young boys and girls playing in leagues from Maine to New Mexico.

In an opinion piece written for CNN, Ed Foster-Simeon, President and CEO at U.S. Soccer Foundation, responded to Coulter's comments by pointing out that soccer is the third largest participation sport in the country and the team sport with the highest growth rate over the past decade.

According to the U.S. Soccer Federation, the governing body for the game in the United States, total attendance at soccer matches in 2013 exceeded 10 million.

Domestic leagues are also experiencing growth with Major League Soccer continuing robust expansion by adding teams in Orlando, New York and Atlanta - with plans for another in Miami.

In May, MLS announced a landmark television rights deal after signing an eight-year agreement with ESPN, FOX Sports and Univision Deportes that will, according to media reports, pour $720 million into league coffers.

Although Americans are currently caught in the grip of World Cup fever it is important not to lose perspective of soccer's place in the United States.

Major League Baseball attendance last season was close to 75 million and that many will be expected through the turnstiles again this year.

And while 25 million set a new benchmark for World Cup viewership in the U.S. the number was dwarfed by the 111.5 million who watched his year's Super Bowl.