Bill Weld William (Bill) WeldRalph Gants, chief justice of Massachusetts supreme court, dies at 65 The Hill's Campaign Report: Biden visits Kenosha | Trump's double-voting suggestion draws fire | Facebook clamps down on election ads Biden picks up endorsements from nearly 100 Republicans MORE, the former Massachusetts governor seeking to challenge President Trump Donald John TrumpFederal prosecutor speaks out, says Barr 'has brought shame' on Justice Dept. Former Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick MORE in a GOP primary, said the president's efforts to pressure Ukraine's leadership into investigating former Vice President Joe Biden Joe BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE's son amount to "treason pure and simple."

"Talk about pressuring a foreign country to interfere and control a U.S. election," Weld said on MSNBC's "Morning Joe."

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"It couldn't be clearer. That's not just undermining democratic institutions. That is treason. It's treason pure and simple."

Fmr. Gov. of Massachusetts Bill Weld: "Talk about pressuring a foreign country to interfere with and control a US election. It couldn't be clearer. That's not just undermining Democratic institutions. That is treason. It's treason pure and simple."https://t.co/PKXEfFVEBp — MSNBC (@MSNBC) September 23, 2019

Weld said Trump should be removed from office for the offense, after noting that the penalty for treason is death. He suggested being removed from office would be "a pretty good alternative" for the president.

It's unclear whether the storm will lead Democrats in the House to impeach Trump.

Speaker Nancy Pelosi Nancy PelosiDemocratic senator to party: 'A little message discipline wouldn't kill us' Overnight Health Care: New wave of COVID-19 cases builds in US | Florida to lift all coronavirus restrictions on restaurants, bars | Trump stirs questions with 0 drug coupon plan Overnight Defense: Appeals court revives House lawsuit against military funding for border wall | Dems push for limits on transferring military gear to police | Lawmakers ask for IG probe into Pentagon's use of COVID-19 funds MORE (D-Calif.) has been hesitant to take that step, partly for fear it would boomerang on Democrats in next year's elections. But pressure on her is growing from Democrats over the Ukraine calls.

The Wall Street Journal reported on Friday that Trump repeatedly pressured Ukraine's leader to investigate Biden and Hunter Biden, the former vice president's son. It is not clear, however, that Trump threatened to withhold aid to Ukraine over the issue, something lawmakers now want to investigate.

Trump has said he did nothing wrong in his communications with Ukraine.

Weld faces an uphill climb in challenging Trump. He is one of three former GOP officeholders doing so, but some state parties have called off primaries to prevent a direct challenge to Trump.

Trump also has broad support within the GOP, according to numerous polls.