Issa said portions of the email probe may extend past the election.
Pence first endorsed Cruz on Friday, but also offered praise for Donald Trump at the time.
In one month, 15 of Trump's campaign events cost local authorities more than $300,000.
Trump argued Cruz can't be president because he wasn't born in the United States.
“Hey Nico, it would be ‘Kay-sick” if you would go to the prom with Julia,” the Ohio governor said.
She tweeted: "Nice job last night. Aunt Hillary approves."
Heidi Cruz referred to husband, Texas Sen. Ted Cruz, as an immigrant during an Indiana campaign stop on Saturday, prompting the campaign to say she misspoke.
“Ted is an immigrant,” Heidi Cruz...