The quixotic late-night filibuster from Sen. Rand Paul, R-Ky., of a bipartisan spending bill last week was only the latest in a series of dramatic reminders that Washington’s troubling new spending boom is created by a de facto alliance between profligate Democrats and the most vociferous and intransigent of conservatives.

In response to the bill’s eventual passage, President Trump tweeted, “Without more Republicans in Congress, we were forced to increase spending on things we do not like or want in order to finally, after many years of depletion, take care of our Military. Sadly, we needed some Dem votes for passage. Must elect more Republicans in 2018 Election!”

Although I would certainly like to see more Republicans in Congress after the 2018 midterms, we also need some of the Republicans already in Congress to vote smarter.

Spending bills originate in the House, where they can pass with a simple majority and where the GOP currently has a comfortable margin. In the Senate, under current practice, they require 60 votes and Republicans have only 51. Under a rational system, the House would pass a spending bill reflecting conservative priorities (generally, increasing defense spending while cutting spending elsewhere), and the Senate would start negotiations with that measure in hand.

In order to pass the Senate, leaders would have to move the bill to the left — presumably increasing nondefense spending — in order to attract Democratic votes. If the 51 Republican senators stuck together, they'd need only nine Democratic votes, and there are 10 Democratic senators running for re-election this year in states that Trump won in 2016. Five of those senators — Joe Manchin of West Virginia, Heidi Heitkamp of North Dakota, Jon Tester of Montana, Claire McCaskill of Missouri, and Joe Donnelly of Indiana — are running in states that the president won by "yuuuuge" margins, between 19 and 42 percent. Adjusting the House-passed conservative spending bill to appeal to enough Democratic senators should be a relatively straightforward task.

In practice, however, President Trump has done a lousy job of consistently applying political pressure to those red-state Senate Democrats. On both tax reform and spending issues, they have felt comfortable defying him and seem to expect there won't be any consequences. (They may or may not be right about that — we’ll find out in November.)

Worse, senators like Paul and a substantial segment of House Republicans refuse to vote for the party-line conservative spending bills that would have to pass to begin the process. They argue that the compromises necessary to get votes from Republicans in more moderate districts will result in spending levels too high for them to support.

The practical impact of this "principled" stand is that the Republican leadership has to secure even more votes from Democrats. And without a united Republican Conference, they can’t just target those red-state Democrats in the Senate — they have to shift the bills far to the left, substantially increasing spending on liberal priorities.

In the House, this problem is particularly acute. The House Republican majority was built in large part by defeating the old moderate, mostly Southern Democrats known as Blue Dogs. So Republicans can’t shift a spending bill slightly to the left and pass it with moderate Democrats, because there aren’t really any left. Now, the bill must move substantially to the left, vastly increasing nondefense spending to attract a broad swath of the Democratic Caucus.

The fiscal situation America faces is undoubtedly dire. According to the nonpartisan Committee for a Responsible Federal Budget, the United States will run $2 trillion annual budget deficits by 2027, and our debt-to-GDP ratio is headed for a level not seen since the end of World War II. Washington Democrats offer no solutions to this problem. Their "Better Deal" agenda offers nothing in the way of spending cuts, real cost savings, or serious consideration of the reforms necessary to put Social Security or Medicare on a sustainable path.

Republicans understand the challenges we face. They know they are falling short in terms of dealing with them. But the fault lies not with the leaders who must deal with Washington Democrats, but with the backbenchers whose refusal to get to "yes" leads to those deals in the first place.

Michael Steel served as press secretary for former House Speaker John Boehner from 2008 to 2015.

If you would like to write an op-ed for the Washington Examiner, please read our guidelines on submissions here.