As a result of redistricting following the 2010 United States Census, Walsh's district was redrawn by the Democratic-controlled Illinois General Assembly in 2012.

[3][6] In the mid-1980s, he embarked on an acting career, taking lessons in stage, theater and television at The Lee Strasberg Theatre and Film Institute in New York City and Los Angeles.

He raised funds for two organizations advocating school choice: the American Education Reform Council, and the Milton and Rose Friedman Foundation.

[13] Walsh also worked on state and local government policy issues for The Heartland Institute, a libertarian free-market think tank based in Chicago.

[15] Walsh won the Republican nomination for Illinois's 9th congressional district and faced longtime Democratic liberal incumbent Sidney R. Yates, who was 87 years old, in the general election.

The district included parts of the northwest Chicago suburbs, such as Arlington Heights, Schaumburg, Gurnee, Palatine, Mundelein, Zion, Barrington, Woodstock and Walsh's home in McHenry.

In February 2010, Walsh won the Republican primary election, taking about 34 percent of the vote in a six-person field and moving into the district from Winnetka in April.

Walsh's campaign responded that the GOP establishment was "a bit tone deaf when it comes to independent, conservative reform candidates".

[28] Walsh criticized Bean for her 2010 votes in favor of the Patient Protection and Affordable Care Act[14] and against the Stupak–Pitts Amendment that would have prohibited the use of federal funds to cover any part of the cost of any health plan that included coverage of abortion.

It appeared that Green Party candidate Bill Scheurer was a factor in the race; he tallied 6,400 votes, far more than Walsh's margin of victory.

At a July 2012 campaign event, Walsh accused his opponent of politicizing both her military service as a helicopter pilot and her Iraq War injuries, which cost her both legs and the partial use of one arm.

[59] Several days before being sworn into Congress, The New York Times criticized Walsh for his willingness to accept donations from political action committees and lobbyists.

He also vowed, "I won't place one more dollar of debt upon the backs of my kids and grandkids unless we structurally reform the way this town [Washington, D.C.] spends money!

"[61] He became a frequent fixture on cable TV,[7][61] advocating a "no compromise" approach to deficit reduction that rejects any tax increases on the wealthy.

[62] Walsh has also said that President Obama was elected "because he pushed that magical button: a black man who was articulate, liberal, the whole white guilt, all of that.

[65] In November 2011, Walsh was videotaped meeting with his constituents, becoming visibly aggressive and swearing at a woman who questioned him about his comment that the marketplace and the banks were not responsible "for the mess we're in right now."

[79][80] After concluding his run for president, Walsh resumed broadcasting in June 2020 with a two-hour call-in talk show on the GAB Radio Network and its Chicago flagship station WCGO.

WIND general manager Jeff Reisman commented: "During the segment Joe intended to cite several common racial slurs as examples.

"[99] in reference to a 13-minute monologue delivered by late night host Jimmy Kimmel discussing his son's congenital heart defect and his belief that covering pre-existing conditions is an important part of healthcare in the United States.

[100] On September 23, 2017, Walsh described Stevie Wonder as "Another ungrateful black multi millionaire" after Wonder had taken a knee at his concert in protest of what he termed police brutality.

"[105] In an interview on This Week on August 25, 2019, Walsh announced that he would enter the 2020 Republican Party primary race, challenging incumbent President Donald Trump.

[114] Following his announcement, Salem Radio Network said it would cancel its national distribution of his talk show on September 26, 2019, and that Walsh will be free to sign up with a different syndicator if he chooses.

"[120] In an interview with Fox News, Walsh reiterated he was willing to support a socialist over Trump in the general election,[121] and he repeated this sentiment in later comments.

[14] Following President Obama's 2011 State of the Union address, Walsh remarked that he did not believe there should be a social safety net because it is not in the Constitution.

[7] In November 2011, Walsh, along with fellow Tea Partier Ron Paul, met leader of the French National Front and anti-Islamist activist Marine Le Pen during her visit to the United States.

[164] Following Walsh's victory in the 2010 Republican primary, it was reported that a bank had foreclosed on his condo and he had been evicted in October 2009, but that he and his family were living in a rented house in the Chicago North Shore suburb of Winnetka at the time.

He was also reportedly facing a lawsuit by a former campaign manager who claimed Walsh owed him $20,000 for services[165] and had federal and state tax liens in the 1980s and 1990s (all paid by 2001).

[3] In July 2011, the Chicago Sun-Times reported that Walsh's ex-wife, Laura, was suing him for $117,437 for past due child support dating from 2005 for their three children.

[61] Walsh's financial problems inspired the proposal of a bill which would forbid people owing more than $10,000 in back child support from running for office in Illinois.

In response, Walsh criticized the Tribune for "wast[ing] time and ink scrutinizing [his] driving record over the last 22 years rather than Washington's unsustainable spending".