House investigators seek documents from Pence as part of impeachment inquiry

WASHINGTON - House investigators want Vice President Mike Pence to give them documents that could shed light on whether he helped President Donald Trump pressure Ukraine to investigate Joe Biden.

In a letter to Pence on Friday, the Democratic chairmen of three House committees cite reports that a Pence aide may have listened to the July phone call in which Trump pushed Ukraine's president to investigate unfounded charges that Biden was involved in corrupt activities there.

They say they also want to learn more about Pence's Sept. 1 meeting with President Volodymyr Zelenskiy.

The letter says there are "questions about any role you may have played in conveying or reinforcing the President's stark message to the Ukrainian President."

Former Vice President Joe Biden is seeking the Democratic presidential nomination.

Earlier Friday, Trump said he will formally object to Congress’ impeachment inquiry even as he acknowledged that House Democrats “have the votes” to proceed.

The White House was expected to send a letter to House Speaker Nancy Pelosi arguing that Congress cannot conduct an impeachment investigation without first having a vote to authorize it. The letter was expected to say the administration won't cooperate with the probe without that vote.

Trump said the resolution would likely pass, but he predicted it would backfire on Democrats.

"I really believe that they're going to pay a tremendous price at the polls," he said.

When Pelosi announced that the House was initiating the inquiry, she didn't seek the consent of the full chamber, as was done for impeachment investigations into former Presidents Richard Nixon and Bill Clinton.

But it is underway, and with a rapidly escalating pace. Late Thursday, House investigators released a cache of text messages that showed top U.S. diplomats encouraging Ukraine's newly elected president to conduct an investigation linked to Biden's family in return for a high-profile visit with Trump in Washington.

The release followed a 10-hour interview with one of the diplomats, Kurt Volker, who stepped down as special envoy to Ukraine after the impeachment inquiry had begun.

Trump repeated on Friday that he was pressing Ukraine to investigate corruption, not trying to undermine Biden, who could be his 2020 presidential election opponent. He made a related request of China, specifying Biden and his son, on Thursday.

As Republicans search for a response to the investigation, the absence of a procedural vote to begin the probe has been a main attack line against Democrats. 

Democrats have sought to use their declared impeachment investigation to bolster their case to access all sorts of documents from the administration, most recently secret grand jury information that underpinned special counsel Robert Mueller's report on Russian interference in the 2016 election. They have also threatened to use the administration's refusal to turn over documents and make witnesses available to potentially form an article of impeachment over obstruction of the congressional inquiry.

Where courts have generally required congressional oversight requests to demonstrate a legitimate legislative purpose, impeachment requests could be wide-ranging.

It is unclear if Democrats would wade into a lengthy legal fight with the administration over documents and testimony — or if they would just move straight to considering articles of impeachment.