WASHINGTON, DC - FEBRUARY 24: Senate Armed Services Committee Chairman John McCain (R-AZ) speaks at a news conference at the U.S. Capitol February 24, 2016 in Washington, DC. The Republican Senators held the conference to speak about President Obama's plan to close the military prison at Guantanamo Bay, Cuba. They called the president's plan 'jibberish,' and said they have tried working with Obama to close the detention camp and move the terrorism suspects held there to federal prisons in the United States but this latest proposal is not the way forward. (Photo by Chip Somodevilla/Getty Images)

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Senate Republicans are looking to tie Hillary Clinton's weaknesses to their Democratic challengers.

Sen. John McCain released a new ad linking his opponent to Clinton's controversies.

CNN  — 

Hillary Clinton’s sliding polls numbers are giving Senate Republicans a new opening, as they plot a more aggressive strategy seeking to tie the party’s presumptive nominee to Democratic challengers across the country.

The latest example: In Arizona, where Sen. John McCain is releasing a new ad Monday seeking to link Rep. Ann Kirkpatrick to Clinton’s controversies. The ad, which was provided to CNN, shows a clip of FBI Director James Comey calling Clinton’s handling of classified emails “extremely careless,” followed by comments by Kirkpatrick saying she backs Clinton.

“She’s served very well as secretary of state, and I’m a Hillary supporter,” Kirkpatrick said in the new ad, which was provided to CNN, and is part of a six-figure buy running statewide in Arizona this week.

Kirkpatrick spokesman DB Mitchell said his boss is “one of the most independent members of Congress.”

“This is the desperate drivel Arizonans have come to expect from John McCain as he tries to save his 33-year career in Washington,” Mitchell said.

Kirkpatrick said in a CNN interview in May that she didn’t plan to attend the Democratic Convention in Philadelphia this week. And other Democratic challengers, particularly, in red states like Missouri, are skipping the week’s festivities.

It all underscores how Democrats in key races across the country could be forced to distance themselves from Clinton, who has grown more unpopular after Comey directly contradicted a number or public assertions the former secretary of state made about her private email server.

A new CNN-ORC out Monday shows Clinton down 5 points to Donald Trump, with a whopping 68% saying she’s not honest or trustworthy. And Republicans say they plan to make Clinton a liability for Democratic candidates as the GOP battles to hang onto their narrow Senate majority.

The strategy to link congressional candidates to the top of the ticket is not unlike the tactics Democrats are employing themselves. Kirkpatrick released a web ad in February seeking to tie Trump to McCain, in a move to dissuade the state’s large Latino voting bloc from backing the veteran Arizona Republican.

McCain himself will have to overcome a GOP primary fight next month before taking on Kirkpatrick in the fall, with polls showing the race neck-and-neck.