On February 9, 2010, Amash announced that he would run for the Republican nomination for Michigan's third congressional district and the next day incumbent Representative Vern Ehlers announced that he would not seek reelection.
During the primary campaign he was endorsed by Betsy and Dick DeVos, the Club for Growth, Representative Ron Paul, and FreedomWorks PAC.
In the Republican primary he defeated four other candidates and shortly before the general election he was named as one of Time magazine's "40 under 40 – Rising Stars of U.S. Politics".
During the campaign he advocated politics supported by the Tea Party movement and defeated Democratic nominee Patrick Miles Jr. in the general election.

The House Republican Steering Committee removed Amash from the House Budget Committee on December 3, 2012, as part of a larger party leadership-caucus shift.
He joined Representatives Tim Huelskamp and David Schweikert in a letter to Speaker of the House John Boehner, demanding to know why they had lost their committee positions.
A spokesperson for Republican Congressman Lynn Westmoreland of Georgia said that Amash, Huelskamp, and Schweikert had been removed for "their inability to work with other members."
Politico said that the three were "the first members pulled off committees as punishment for political or personality reasons in nearly two decades".

Following the retirement of Senator Carl Levin it was speculated that Amash would run in the 2014 Senate election and Senator Mike Lee encouraged him to run, but Amash chose to run for reelection to the House.

Amash was endorsed by the fiscally conservative Club for Growth PAC, which spent over $500,000 supporting Amash in his Republican primary against former East Grand Rapids School Trustee Brian Ellis, who was endorsed by the U.S. Chamber of Commerce and spent more than $1 million of his own money on the race.

After Amash defeated Ellis in the August primary, with 57% of the vote to Ellis's 43%, Amash was highly critical of Ellis and former Congressman Pete Hoekstra, who had backed Ellis.
Of Hoekstra, Amash said, "You are a disgrace.
And I'm glad we could hand you one more loss before you fade into total obscurity and irrelevance."
Amash took exception to one of Ellis's television ads that quoted California Republican Congressman Devin Nunes calling Amash "Al Qaeda's best friend in Congress"; he demanded an apology from Ellis for running what he called a "disgusting, despicable smear campaign."
As Conor Friedersdorf of The Atlantic notes, "Amash voted against the reauthorization of the Patriot Act, favored a measure to repeal indefinite detention, and opposed reauthorization of the FISA Amendments Act."
In the general election, Amash won reelection against Democratic nominee Bob Goodrich.

In 2011, Amash endorsed Representative Ron Paul's campaign for the Republican presidential nomination.
In 2015, he endorsed Senator Rand Paul's campaign for the Republican presidential nomination and later endorsed Senator Ted Cruz after Paul dropped out.
On February 9, 2010, Amash announced that he would run for the Republican nomination for Michigan's third congressional district and the next day incumbent Representative Vern Ehlers announced that he would not seek reelection. During the primary campaign he was endorsed by Betsy and Dick DeVos, the Club for Growth, Representative Ron Paul, and FreedomWorks PAC. In the Republican primary he defeated four other candidates and shortly before the general election he was named as one of Time magazine's "40 under 40 – Rising Stars of U.S. Politics". During the campaign he advocated politics supported by the Tea Party movement and defeated Democratic nominee Patrick Miles Jr. in the general election.
The House Republican Steering Committee removed Amash from the House Budget Committee on December 3, 2012, as part of a larger party leadership-caucus shift. He joined Representatives Tim Huelskamp and David Schweikert in a letter to Speaker of the House John Boehner, demanding to know why they had lost their committee positions. A spokesperson for Republican Congressman Lynn Westmoreland of Georgia said that Amash, Huelskamp, and Schweikert had been removed for "their inability to work with other members." Politico said that the three were "the first members pulled off committees as punishment for political or personality reasons in nearly two decades".
Following the retirement of Senator Carl Levin it was speculated that Amash would run in the 2014 Senate election and Senator Mike Lee encouraged him to run, but Amash chose to run for reelection to the House.
Amash was endorsed by the fiscally conservative Club for Growth PAC, which spent over $500,000 supporting Amash in his Republican primary against former East Grand Rapids School Trustee Brian Ellis, who was endorsed by the U.S. Chamber of Commerce and spent more than $1 million of his own money on the race.
After Amash defeated Ellis in the August primary, with 57% of the vote to Ellis's 43%, Amash was highly critical of Ellis and former Congressman Pete Hoekstra, who had backed Ellis. Of Hoekstra, Amash said, "You are a disgrace. And I'm glad we could hand you one more loss before you fade into total obscurity and irrelevance." Amash took exception to one of Ellis's television ads that quoted California Republican Congressman Devin Nunes calling Amash "Al Qaeda's best friend in Congress"; he demanded an apology from Ellis for running what he called a "disgusting, despicable smear campaign." As Conor Friedersdorf of The Atlantic notes, "Amash voted against the reauthorization of the Patriot Act, favored a measure to repeal indefinite detention, and opposed reauthorization of the FISA Amendments Act." In the general election, Amash won reelection against Democratic nominee Bob Goodrich.
In 2011, Amash endorsed Representative Ron Paul's campaign for the Republican presidential nomination. In 2015, he endorsed Senator Rand Paul's campaign for the Republican presidential nomination and later endorsed Senator Ted Cruz after Paul dropped out.
Justin Amash