The official biographies on are taken from “The Presidents of the United States of America” by Michael Beschloss and Hugh Sidey, a book published by the White House Historical Association.

In an addition to Ronald Reagan’s (R) biography, Obama’s proposal to raise taxes on the wealthy through the so-called “Buffett Rule” is compared to Reagan’s call for a fairer tax code. Obama has referred to Reagan in the past, in speeches and on a separate website, as a foundational supporter of the principle behind the rule.

The healthcare reform bill is referenced on Lyndon Johnson’s (D) biography, and Obama's “all of the above” energy initiatives on Jimmy Carter’s (D) bio page.

Rory Cooper, the communications director at conservative think tank the Heritage Foundation, first noticed the additions in a tweet on Tuesday.

The topic took off from there, with conservative pundits Erick Erickson and Michelle Malkin sharing jokes and even pictures of Obama added to iconic pictures.

The Republican National Committee rushed to set up a Tumblr on the topic, as well, adding Obama to historical events such as the fall of the Berlin Wall and celebrating V-J Day in Times Square.

The conservative criticism was also picked up by Comedy Central, with a post on its popular Indecision blog.

The National Republican Congressional Committee jumped in as well, joking that Obama told former Vice President Gore to invent the Internet for the sake of Julia, a mash-up of conservative in-jokes.

Gore has been widely lambasted for claiming “initiative in creating the Internet” in a 1999 interview. And Julia is a fictional female character created by the Obama campaign to illustrate policies the president believes will help American women.

The number of tweets spiked shortly after 11 a.m., according to an analysis at Topsy, but quickly tapered off in the afternoon.

—This story was updated at 4:40 p.m.