[15] In June 2006, while stationed in Iraq, Cotton gained public attention after writing an open letter to the editor of The New York Times, asserting three journalists had violated "espionage laws" by publishing an article detailing a classified government program monitoring terrorists' finances.

In 2018, Adam Albrett of Fairfax County, Virginia, was arrested for "faxing death threats" against President Donald Trump and members of Congress, including Cotton.

[60][61] In January 2020, 78-year-old Henry Edward Goodloe was sentenced to two years' probation for sending Cotton a threatening letter and a package containing white powder.

The Senate mail facility intercepted the letter, which included Goodloe's home address, and alerted a hazardous response team which determined the powder was unbleached flour and starch.

[70][71] With less than two months to the next presidential election, Cotton supported an immediate Senate vote on Trump's nominee to fill the Supreme Court vacancy caused by Justice Ruth Bader Ginsburg's death.

In March 2016, Cotton refused to consider Obama's Supreme Court nominee during a presidential election year, providing his rationale with these questions: "Why would we cut off the national debate on the next justice?

The bill earmarked $45 billion more for Ukraine to defend itself against Russia, but prohibited funding for more immigration barriers in the U.S. and did not raise border enforcement spending past current inflation levels.

"[83] Arguing against the bill in question, the FIRST STEP Act, Cotton asserted that "convicts of certain sex-related crimes could accrue credits making them eligible for supervised release or 'pre-release' to a halfway house".

[86] Amid the ensuing protests, Cotton advocated on Twitter that the military be used to support police, and to give "no quarter for insurrectionists, anarchists, rioters, and looters".

[93] Cotton criticized the Times for retracting his piece, saying, "The New York Times editorial page editor and owner defended it in public statements but then they totally surrendered to a woke child mob from their own newsroom that apparently gets triggered if they're presented with any opinion contrary to their own, as opposed to telling the woke children in their newsroom this is the workplace, not a social justice seminar on campus".

[94] In July 2020, Cotton introduced the Saving American History Act of 2020, proposed legislation preventing the use of federal tax dollars for the teaching of The 1619 Project, an initiative of The New York Times.

"[98] Joshua D. Rothman, a history professor at the University of Alabama, responded that slavery was neither "necessary" nor on the way to "extinction" when America was founded, because it "was a choice defended or accepted by most white Americans for generations, and it expanded dramatically between the Revolution and the Civil War".

[100] Georgetown University historian Adam Rothman said Cotton's phrase is "really a kind of shorthand way of describing the complex set of attitudes of the founding generation and it's not really accurate.

[114] On February 7, 2017, in the presence of President Trump, Cotton and Senator David Perdue proposed a new immigration bill, the RAISE Act, which would limit the family route or chain migration.

PolitiFact rated Cotton's claim as "False" and elaborated that the "Biden's administration ordered a 100-day deportation pause, but it did not apply to criminals such as murderers, rapists, terrorists or gang members.

[129][130] In April 2019, Cotton called the Southern Poverty Law Center a "political hate group" and asked the IRS to check whether it should retain its tax-exempt status.

He preferred a solution that ended what he called the "federal-government monopoly on the student-lending business", referring to the provision of the Patient Protection and Affordable Care Act that changed the way the federal government makes student loans.

[140] On January 6, 2021, Cotton released a statement repudiating the attack on the Capitol:[141] Last summer, as insurrection gripped the streets, I called to send in the troops if necessary to restore order.

Those who attacked the Capitol today should face the full extent of federal law.He subsequently repeated his earlier description of those involved as "insurrectionists" and said they should be brought to justice.

[144] Cotton was among the 31 Senate Republicans who voted against final passage of the Fiscal Responsibility Act of 2023, citing a provision in the bill that would limit defense spending increases to a lower rate than inflation.

[153] In December 2018, after Trump announced the withdrawal of American troops in Syria, Cotton was one of six senators to sign a letter expressing concern about the move and their belief "that such action at this time is a premature and costly mistake that not only threatens the safety and security of the United States, but also emboldens ISIS, Bashar al Assad, Iran, and Russia.

"[154] In January 2019, Cotton was one of 11 Republican senators to vote to advance legislation intended to block Trump's intent to lift sanctions against three Russian companies.

[160] In August 2018, Cotton and 16 other lawmakers urged the Trump administration to impose sanctions under the Global Magnitsky Act against Chinese officials who are responsible for human rights violations in western China's Xinjiang region targeting the Uyghur ethnic minority.

[161] They wrote in a bipartisan letter, "The detention of as many as a million or more Uyghurs and other predominantly Muslim ethnic minorities in 'political reeducation' centers or camps requires a tough, targeted, and global response".

The bill would also codify Trump's executive order from the previous May that empowered his administration to block foreign tech companies deemed a national security threat from conducting business in the United States.

"[196] On November 9, 2023, Cotton asked the Department of Justice to investigate whether journalists working for international news outlets "committed federal crimes by supporting Hamas terrorists".

[199] After the ICC issued arrest warrants for Netanyahu and Yoav Gallant on November 21, 2024, Cotton called it a "kangaroo court" and the prosecutor, Karim Khan, a "deranged fanatic."

[208] President Obama mocked the letter, calling it an "unusual coalition" with the Islamic Revolutionary Guard Corps as well as an interference with the ongoing negotiations of a comprehensive agreement on the Iranian nuclear program.

[215] In July 2018, Cotton introduced the Iran Hostage Taking Accountability Act, a bill that would call for the president to compose a list of Iranians that were "knowingly responsible for or complicit in...the politically-motivated harassment, abuse, extortion, arrest, trial, conviction, sentencing, or imprisonment" of Americans and have those on the list face sanctions along with enabling the president to impose sanctions on their family members and bar them from entering the United States.

[147] On March 13, 2018, in an interview on conservative commentator Hugh Hewitt's radio show, Cotton said he expected Russian officials to "lie and deny" about the poisoning of Sergei Skripal, an ex-Russian spy on British soil.