The government shutdown is over, but its end marks the beginning of a new era of American politics. While the political world spent the last year fixated on President Trump, the under-reported story is the incredible transformation of the Democratic Party, something that will have a big impact on both policy debates and electoral politics.

In short, Democrats have evolved into a base-driven, radicalized party, embracing not only an increasingly liberal platform but also the kind of burn-it-down tactics that repel independent, educated, and suburban voters.

It’s a shift that’s come so fast and furiously that voters are largely unaware of it, and Democratic political operatives hoping to win congressional races want to keep it that way. Democrats would like the 2018 midterms to be a national referendum. Targeted Republicans in battleground areas, however, should not simply play defense. They should contrast their accomplishments with the increasingly liberal Democratic Party. They should make 2018 a choice.

Just look at the Left today. The moderate, pro-business Blue Dogs are nearly extinct. Of the 32 Democrats in the House of Representatives who voted against Obamacare in 2009, only two of them are still in Congress today. This is not your father’s Democratic party. The recent government shutdown should make that clear. For anyone paying attention, this is now the party of Elizabeth Warren. If Democrats win back the House majority this fall, Maxine Waters is in line to become the next chair of the House Financial Services Committee. If Democrats take back the Senate, Bernie Sanders will become chairman of the Senate Budget Committee.

More than a third of the Democratic conference in the Senate has endorsed Sanders’ “Medicare for All” bill, which would cost, according to some estimates, $32 trillion over 10 years. In the House, the swing to the far Left is even more striking with more than 60 percent of Democrats endorsing John Conyers’ “Medicare for all” bill to nationalize health insurance.

This is not a straw man argument or conservative fear mongering. Single-payer healthcare is undeniably the stated policy position of the majority of the House Democratic conference.

Shining a light on the liberalism of modern Democrats will be critical for Republicans holding the House. Historically, the incoming president’s party gets clobbered in the first midterm election, losing on average 32 seats in the House. Voter enthusiasm and participation are typically higher among an energized angry opposition than they are among the content ruling party. For example, in 2010, the House Democrat majority lost a whopping 63 House seats. The current Republican advantage in the House stands at 24 seats.

The liberal enthusiasm has, however, proven helpful in one key way for Republicans. Across the country we’re seeing packed Democratic primaries with multiple candidates all trying to move one step to the left of each other. In Virginia, one Republican-held seat has 10 Democratic challengers in the primary. When they’re all settled, it will not be hard to make the case that Democrats are the party of single-payer healthcare and higher taxes.

But defining the other side is not enough. Republicans should promote their record of accomplishments (tax cuts most especially) and tout the strong economy. Already more than 3 million workers have received bonuses as a result of the Tax Cuts and Jobs Act of 2017. Energy costs are coming down thanks to this reform. Jobs, profits, and companies themselves are already coming home. Most importantly, more than 90 percent of workers will soon see more in their paycheck, with the average family seeing a tax cut of more than $2,000 this year. Since the tax cuts passed, their popularity has risen dramatically alongside soaring economic confidence.

Of course, not a single Democrat in Congress voted for these tax cuts. There’s no room for lower taxes, economic expansion, and free market principles in today’s Democratic Party. By focusing on the stark contrast between the Republican policy agenda and the one outlined by today’s Democratic Party, Republican candidates will be well equipped to stem the tide this fall.

Jake Kastan has been a political aide to Paul Ryan since 2012. He is deputy executive director of Team Ryan, Paul Ryan’s political office.

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