File photo: REUTERS/Yuri Gripas.

WASHINGTON – Congressional Republicans are sticking with their party leader in the face of thousands of pages of evidence showing President Donald Trump leveraged foreign policy for political favours, raising the possibility that not a single House Republican will vote for his impeachment.

As they prepare to hold the first open impeachment hearings this week, Democrats had hoped to peel off Republican support from a key GOP bloc – retiring lawmakers who need not worry about internal blowback or primary challenges.

Yet many are refusing to break with Trump. Rep. Peter King of New York made a point of stating his intention to vote against impeaching Trump in his retirement announcement Monday, a troubling sign for Democrats.

Another moderate Republican, Rep. Will Hurd of Texas, sounded more like a Trump ally than a centrist on a Sunday morning talk show as he called for Hunter Biden, son of former vice president Joe Biden, to testify in the impeachment inquiry – an idea being pushed by the White House that concerns some conservative Senate Republicans. Hunter Biden served on the board of a Ukrainian gas company.

In more than five weeks of testimony, current and former Trump administration officials allege that the president tied foreign aid and a White House meeting to Ukraine’s willingness to investigate the Bidens and a conspiracy theory surrounding the 2016 election.