Washington (CNN) Former Massachusetts Gov. Bill Weld's numbers against President Donald Trump aren't looking good for him -- or any other Republican who decides to challenge the President for the 2020 Republican presidential nomination.

Only 8% of Republicans and Republican-leaning independents said they would definitely support Weld in a matchup against Trump and 10% said they weren't sure but could support him, according to a March poll conducted by Monmouth University . Over half (54%) said they would definitely be supporting Trump, and 2 in 10 also reported they would probably support Trump but consider Weld as an option.

With just 8% definite and 30% possible, it's not a good base for the former governor as he starts his official campaign.

Weld's biggest support comes from moderate and liberal Republicans and leaners, 16% of whom said they would definitely support him over Trump.

Unfortunately for Weld, only 4% of registered Republicans in Iowa, the first primary state to hold a caucus, have a favorable opinion of him, according to the March CNN/Des Moines Register/Medicom poll . Few, however, have an unfavorable opinion of him -- 81% said they aren't sure.

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