President Obama's trip last week underscored one thing: He's more popular abroad than he is at home.

Crowds lined the streets of Brussels, The Hague and Rome to catch a glimpse of Obama's motorcade. The crowd watching Obama's speech at the Palais des Beaux Arts in Brussels was described as "star-struck." 

Obama is so popular in the Netherlands, where he began his trip, that there's an Obama Club, PRI reports. Its members get together and discuss issues relevant to Obama's presidency, including foreign policy and diversity.

"These countries in Western Europe are really Obama countries," historian Willem Post told the PRI radio show "The World." "I think that has to do with the fact that this is a U.S. president who calls himself a global citizen [and urges] diplomacy first."

Even Obama's comic turn with Zach Galifianakis on "Between Two Ferns," where Obama plugged, was covered by a Dutch newspaper.

Obama has long been viewed as a rock star of sorts in Europe. In 2008, nearly 200,000 people watched him give a speech in Berlin. Last year, during his speech at Brandenburg Gate, Obama shed his jacket during sweltering weather.

"Thank you for this extraordinarily warm welcome. In fact, it’s so warm, and I feel so good that I’m actually going to take off my jacket,” he said. “We can be a little more informal among friends."

Republicans have seized upon Obama's rock star status in Europe, most famously in John McCain's 2008 ad asking if the biggest celebrity in the world was ready to lead.

But however popular Obama is in Europe, he is overshadowed by another: Pope Francis. During a recent meeting with the pope, Obama joked that Francis might be the only person on Earth who has to put up with more officialdom.

"His Holiness is probably the only person in the world who has to put up with more protocol than me," Obama said.