Montana state auditor Matt Rosendale launched a new website on Monday detailing how Sen. Jon Tester (D-MT) has supported 99 percent of Barack Obama’s judicial nominees, while he has opposed President Donald Trump’s Supreme Court nominee Neil Gorsuch.

Rosendale, who hopes to unseat Sen. Tester in the 2018 midterm election, details the Montana Democrat’s support for Obama’s judicial nominees and how he has continued to oppose Trump’s nominees in comparison.

Rosendale said in a statement:

Jon Tester needs to be held accountable for his extreme partisan liberal record of supporting President Obama’s judicial nominees 99% of the time but then opposing President Trump’s nominees. Look at the Supreme Court, Tester voted for President Obama’s nominations of Sonia Sotomayor and Elena Kagan but opposed President Trump’s nomination of Neil Gorsuch. That’s not representing our Montana values.

Tester voted to confirm Obama’s Supreme Court Justice nominees, Elena Kagan and Sonia Sotomayor. Sotomayor has disputed whether Americans have a Constitutional right to bear arms.

Sotomayor wrote in one 2004 opinion, “the right to possess a gun is clearly not a fundamental right.”

Ken Blackwell, a senior fellow with the Family Research Council, called Obama’s pick at the time a “declaration of war against America’s gun owners.”

Tester also voted against two-thirds of Trump’s Circuit Court nominees.

The National Rifle Association Institute for Legislative Action (NRA-ILA) backed Judge Brett Kavanaugh for the Supreme Court. The NRA-ILA wrote last week, “Throughout his time on the bench; Judge Kavanaugh has demonstrated deep respect for the Second Amendment as construed in Justice Antonin Scalia’s.”

Sen. Tester has also yet to state whether he will back President Trump’s current Supreme Court nominee, Judge Brett Kavanaugh. In contrast, Rosendale came out strongly in favor of Kavanaugh, saying, “I’m a straight shooter, I’ll stand with the people of Montana and President Trump to support Kavanaugh’s nomination because there is no doubt that he will defend our Constitution and protect our Montana way of life.”

Rosendale concluded in his statement on Monday, “I’m running to stand with the people of Montana and support President Trump’s judicial nominees. We need more justices who will uphold the Constitution, follow the rule of law, and protect our Montana way of life.”