A political party serves two fundamental purposes.

First, people form and join political parties to advance policy.  (Of course, there are disagreements on the exact priorities or the specific details of policy proposals.)  In fact, one of the biggest mistakes that the Framers made was not anticipating that, once there were elections for federal offices, the groups in New Jersey that favored rural farmers over “urban” merchants would unite with similar groups in Georgia (and vice versa for the groups that favored merchants) rather than stay isolated in their own states.  Simply put, if you want a single-payer health care system, you are more likely to get it by forming a large group with other supporters of that type of proposal than working on your own.

Second, the way that political parties try to advance policy is by getting their candidates elected to office.  You can’t pass a single-payer system if the opponents of single-payer have the majority in Congress or control the White House.  And political parties win elections by finding good candidates and raising and spending money to support those candidates.   Especially in the year before the election, money tends to be spent on creating tools (like voter databases and helping state parties) that are available to all candidates that run on the party’s ticket.  And at this point in time, with the exception of the last handful of state primaries, the parties have their candidates.

In the last half of the election year, however, the parties start spending in two other significant ways.  First, they build up field organizations (the “coordinated campaigns”) in key states.  Second, they spend money in specific races.  And right now is a key time for the parties making decisions as to where they are going to send/hire staff and run ads.  The simple reality is that, like with anything else in economic life, political parties only have a limited amount of money to spend.  If money was unlimited, the parties could hire a field organizer for every county in the country and multiple organizers for the larger counties  and purchase a large number of ads for every race from president down to county assessor.  Of course, the political parties (and their various national and state committees) only have a limited amount of money to spend.  So the political parties have to make spending decisions.

For national spending, there are two key considerations that play into staffing decisions.  First, what states are competitive for the presidential election?  Second, what states have other crucial competitive races?  For campaign spending, on the other hand, the sole question is what races are competitive?

So, with all that as background, the two parties are about to have to make decisions on which Senate races deserve those scarce resources.  Some states (e.g., Arizona) may get staff resources despite the Senate race slipping away because the Trump campaign simply can’t concede the state and the numbers look good enough for Biden that he will put some resources into Arizona to give him more ways to win.   In making this decision, a lot depends upon which party has the most “at-risk” senators and representatives. For the most part, challengers are not present in D.C. where they can pester the leaders of their party for help.  (Their campaigns can still call, but it is much easier to resist a phone call than for your party leaders to say “no” to their colleague whom they see daily and rely upon for tough votes on a regular basis.)  On the other hand, the incumbents are there in D.C. to lobby one-on-one for help.  And this year, almost all of the at-risk seats are held by Republicans.

For the Democrats, there are “maybe” three incumbents who might need help. Unfortunately, Doug Jones in Alabama may not get the help that he wants.  Alabama is just too red.    The other two states that might be at risk — Minnesota and Michigan — seem to not be moving in the Republican favor.  Since both are potential swing states for the presidential race, both states will get campaign staff and there will be some initial spending on the Senate.  But funds may move away from these states if the numbers continue to look good for holds.

The Republicans, on the other hand, have the difficult decision of having too many incumbents to defend.  If the election were today, it looks like the Republicans will certainly lose Colorado and Arizona and could easily lose North Carolina and Maine with Iowa, Montana, South Carolina, and the regular Senate race in Georgia being too close to call.  (The weirdness of the special election in Georgia should keep the Republicans on the sideline.  However, if it looks like one Democrats is emerging as the clear choice for Democrats, you could see both parties get involved in that race to either get that candidate into — or keep that candidate out of — the top two.)   The real issue for now is when will the Republicans decide to abandon Colorado and Arizona (and maybe even Maine or North Carolina).  I think Colorado and Maine are probably the first to be cut.  Between them, they have, at most, one electoral college vote up for grabs.  And, with ranked choice voting, Senator Collins probably needs to get 49% of the first choice votes to win.  On the other hand, shoring up the Republican base in Arizona and North Carolina also helps President Trump, who needs both states to have any chance at re-election.  (There are paths to 270 in which Trump loses both states, but those paths are real long shots.)

However, the early September decisions on where to spend money is not the final decision.  You could see some early spending in states like North Carolina in which voting has already started.   However, by mid-October with half of the votes already cast, the parties could decide to shift their focus elsewhere.  In particular, if President Trump is still in bad shape by mid-October, the Republican leadership in the Senate could decide that it is up to them to save the few seats that they can to keep the Senate close regardless of what the White House wants to have happen.

Of course, no political party ever announces that they have given up on a Senate race.  For on the record statements, the Republicans are confident that Senator McSally and Senator Gardner will be re-elected.  Off the record, however, their opinions are quite different.  And those opinions will be expressed by whether those statements of support are backed up with advertising and staffing.  And we will start hearing, and to some degree have already seen, where and when the parties are booking ads.