Joe Cunningham is an editor at the conservative news and opinion site, RedState.com, and a contributor to TheHayride.com. You can follow him on his Twitter account, @joepcunningham. The opinions expressed in this commentary are his own.

(CNN) Tuesday, June 26, 2018, should go down as a great day for Donald Trump. He had a big win in the Supreme Court on his travel ban, and several moderate Democrats were defeated by more extreme left-wing candidates.

Joe Cunningham

Among them is avowed socialist Alexandria Ocasio-Cortez, a 28-year-old Latina woman who defeated Joe Crowley, dealing a major blow to Democratic leadership in the House. Crowley was considered by many the likely next Democratic speaker.

This is a pretty big deal for Democrats, as they search for a way to defeat the Republican Party in 2018 and Donald Trump in 2020.

This push further left can have disastrous effects for the Democrats, however, and the one who will ultimately reap the rewards is Trump. The risk is that candidates chosen in Democratic primaries will advocate views that are too far left for the voters who will show up in the November election.

Originally, the Democrats were looking at a "blue wave," a chance to wipe out a lot of Republican gains from the past 10 years. That wave, however, could turn out to be more of a ripple.

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