Trump and his campaign are pouncing on the Virginia senator as an opportunity to draw a fresh contrast between Trump's outsider brand and Clinton's status as a decades-long Washington insider -- a contrast Trump drew successfully time and again with his GOP primary opponents.
The campaign is raising everything from the gifts Kaine received during his time as Virginia's governor to his past support for the Trans-Pacific Partnership trade deal to label the newly formed Democratic ticket as guarantors of the "rigged system" Trump has so often decried on the campaign trail.
"If we went to central casting for someone who gives us the clearest contrast against the Trump-Pence ticket, they couldn't have picked a better person from our perspective," a senior Trump adviser said. "They are doubling down on the status quo. They are doubling down on the system as it currently stands."
The campaign will continue to draw that contrast in the coming days as Trump hits the campaign trail in crucial swing states such as Florida and North Carolina in addition to poking holes in Kaine's record as governor, the adviser said. The campaign began challenging Kaine by blasting out opposition research on Saturday and will continue to knock Kaine's record on job creation, taxes and the size of government, the adviser said.
Less than two hours after Clinton announced she had picked the junior senator from Virginia, the Trump campaign pumped out highlights from a recent news report that raised the more than $160,000 in gifts
Kaine received from businesses and political donors during eight years as Virginia's lieutenant governor and governor.
"If you think Crooked Hillary and Corrupt Kaine are going to change anything in Washington, it's just the opposite," Trump's senior communications adviser Jason Miller said in a statement, revealing a new moniker for Clinton's running mate. "It's only fitting that Hillary Clinton would select an ethically challenged insider like Tim Kaine who's personally benefited from the rigged system."
Kaine spokeswoman Amy Dudley rebutted the corruption allegations, insisting Kaine "went beyond the requirements of Virginia law, promptly disclosing any and all gifts received, including those beneath the reporting threshold."
"All disclosure information -- the vast majority of which was for work-related travel expenses rather than gifts -- has been publicly available for years and never once raised any concerns of impropriety," Dudley said in a statement.
The Clinton campaign declined to respond to a request for comment on the Trump campaign's allegations about Kaine.
Kaine is a well-respected figure on Capitol Hill, known for his initial skepticism of the Iran nuclear deal and his unrelenting calls for Congress to pass a new authorization of military force in the fight against ISIS -- earning him the praise of some Republicans.
"Trying to count the ways I hate @timkaine," tweeted Sen. Jeff Flake, R-Arizona. "Drawing a blank. Congrats to a good man and a good friend."
But the Trump campaign pressed forward Saturday morning, blasting out additional opposition research pressing forward with its assault on Kaine that labeled him a "career politician" lacking a signature accomplishment as governor.
Trump followed up his campaign's messaging in a series of tweets Saturday morning that accused Kaine of being "owned by the banks" and slammed his support for the Trans-Pacific Partnership, which Trump has railed against during his campaign.
"Tim Kaine has been praising the Trans Pacific Partnership and has been pushing hard to get it approved. Job killer!" Trump tweeted, despite the fact that his own running mate has also voiced support for the TPP deal.
Miller, a Trump campaign spokesman, rejected the comparison between Indiana Gov. Mike Pence's support of TPP and Kaine's.
"Both Hillary Clinton and Tim Kaine have supported bad trade deal after bad trade deal, and given their track records, nobody has confidence in their ability to negotiate for trade deals that actually help American workers."
The Trump campaign is working to upend the perception that Kaine, a moderate Democrat with decades of political experience and strong national security credentials, was a safe pick. Instead, it is using Kaine's selection as fresh ammo to fuel its characterization of Clinton as a corrupt figure.
And it's also seizing the opportunity to try and siphon off supporters of Sen. Bernie Sanders, Clinton's chief opponent in the Democratic primary whose fighting rhetoric against special interests and free trade deals defined his campaign.
Trump made his latest appeal to Sanders supporters Saturday morning, tweeting that they "are furious with the choice of Tim Kaine, who represents the opposite of what Bernie stands for."
"Bernie supporters are outraged," Trump tweeted. "Bernie fought for nothing!"
While Sanders and his most prominent supporters have emphatically rejected the possibility of his supporters moving to Trump's campaign, Clinton's pick has drawn a mixed response from progressive groups worried the Kaine pick could allow Trump to "outflank" Clinton on trade.
And Trump campaign advisers believe they can also use Kaine to highlight an enthusiasm gap between the Republican and Democratic tickets.
"They went with an insider who generates little to no enthusiasm for their base, who's wrong on the core issues and who represents everything that is wrong with the rigged system that we see in Washington today," the senior adviser said.
The Trump campaign, sometimes known for its haphazard, disorganized messaging, is hewing closely to its talking points on the Kaine issue.
"The Kaine VP pick does nothing but hurt Hillary Clinton because it plays into the narrative that the Democrats are bought and sold by special interests," Boris Epshteyn, a Trump campaign surrogate, said Saturday on CNN. "Both the Clintons and Tim Kaine have a lifelong history of taking money from special interests and being bought and paid by those special interests."