You might be thinking the Democratic base is fired up to oppose Donald Trump and his hate-mongering, xenophobic, racist ways.  You’d be right.  Of course, it also forced the party to forfeit any ability to contest Donald Trump’s plan to reshape the American Judiciary and increasingly is making them look out of touch and ideologically rigid to persuadable swing voters.

But there is another lesson Democrats should look to.  For as Republicans learned in years past,  an excited grassroots is as much a curse as it is a blessing for a party.

On the one hand, the benefits of a fired up base are plain to see.  Jon Ossof in Georgia raised a whopping eight million dollars for a special election in Tom Price’s old district.  Democrats are actually worrying the GOP enough they are spending money and time to win a district in KS-4 Trump won by 27 points last November.

But, Democrats might be doomed to repeat the mistakes of the Senate GOP in 2010 and 2012. Those years, conservative Republicans and Independents helped defeat several strong Republicans in primaries and the party lost winnable races as a result.  Republicans finally developed a counter-strategy in 2014 and last year.

Anger against the establishment and support for ideological purity drove GOP voters to oust moderate and somewhat conservative candidates in years past.  This time, it looks like Democrats are set to do the same but for one different reason, candidates are not opposed enough to Trump.

Several prominent examples come to mind.   Conservative Democratic Congressman Dan Lipinski represents Illinois-3, a suburban Chicago district that backed Obama and Clinton by 12 and 15 points.  Among Lipinski’s apostasies are his opposition to gay marriage in 2014, his support for a bill this year that banned federal funding for abortion services and his support of a overturning an HHS rule that allowed money to go to Planned Parenthood and other state organizations that provide abortion services.  But, the worst might be his recent support for a local GOP town mayor that won by 100 votes.  His declared opponent, Marie Newman, plans to challenge him from the left.

In West Virginia, Joe Manchin represents a state electorate that backed Donald Trump by 42 points.   Manchin has backed a majority of Trump’s Cabinet appointees and he also supported Neil Gorusch for the Supreme Court not just for closure but also final confirmation. Liberal Democrats, instead of realizing they should be content with a guy that opposes Trump some of the time have already begun funding a primary challenger fund.

Unsurprisingly, other ominous primary threats have begun to circulate regarding Senators Heidi Heidikamp and Joe Donnelly of North Dakota and Indiana.  And while primary challenges might not be popping up for Senators Claire McCaskill and Jon Tester, the possible fear of one is driving them to oppose Trump in states where a majority of voters (not their base) want them to work with Trump.

The deja vu feeling Republicans must be feeling at seeing Democrats go through their pain is understandable.  Just utter the words “I am not a witch” and any good Republican consultant will cringe.  The same for Sharron Angle’s famous Asians look like Hispanics comment and the oh so famous Todd Akin and Richard Mourdock gaffes on abortion (gift from God and body has a way to prevent pregnancy during rape).

But, this time it is Democrats feeling the pain and much as Republicans were uncertain what to do way back when so are Democrats now.  Party leadership is not taking a side in the fight which in a way is a side.  After-all, when liberal groups called for Manchin to be removed from leadership the party did not move a finger.  This might ultimately benefit Manchin who has a reputation with state voters dating back to his time as Governor.

But for McCaskill, Tester, and Donelly, who do not have the connections with voters Heidikamp or Manchin have, the damage could prove permanent if it means the party faithful not just support a primary challenger but refuse to turn out in the general election.

For McCaskill, facing a threat from a conservative Congresswomen with four times the cash on hand as the sitting Senator, the threat is daunting.  McCaskill has behaved more like a liberal Democrat from California than a Senator from a state that backed Trump by 19 points.  As a result, she might avoid a primary challenge, but she will probably lose reelection even if the political environment favors her party.

Whether Democrats recognize their base is jeopardizing their chances at any semblance of control at the federal level before 2020 remains to be seen.  Republicans certainly did not and argued over and over the enthusiasm benefited their efforts.  In the end it did but it cost them quite a lot in the Senate over the next few elections.  Democrats seem set to repeat their mistakes.