WASHINGTON (CNN) The year's first TV ad blitz of the Democratic presidential race hit the airwaves this week, promoting Washington Gov. Jay Inslee and his vow to combat climate change.

But instead of coming from Inslee's campaign, the ads were funded by a super PAC that an Inslee ally helps run.

The early spending by the pro-Inslee group underscores how super PACs unleashed by the Supreme Court's blockbuster Citizens United ruling nearly a decade ago, and other court decisions that followed, still will play a role in the 2020 campaign even as they pose political risks for candidates.

Super PACs, which can raise and spend unlimited amounts of money to influence elections, have become one of the most potent tools in modern politics -- allowing wealthy donors to spend millions of dollars to boost favored candidates. But the Democratic Party's liberal activists warn of super PACs drowning out the voices of average voters and have sought to make rejecting big money a litmus test for Democratic candidates.

In a field crowded with candidates competing for campaign dollars, however, super PACs offer a route for little-known candidates to break out.

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