I am not sure which events are decisive in a presidential race, but I’m quite certain that among the least important but most discussed are endorsements and the selection of running-mates.

Both are very public events, often surrounded with plenty of hoopla, speculation and media frenzy. And very rarely, an endorsement or a running-mate does matter in the election. But most of the time, neither one has much of an impact on a presidential race’s outcome.

Endorsements are not decisive because voters know the candidates and have plenty of information to decide for themselves who is prepared to be president, who they agree with on the issues, and who they trust to do the right thing. The candidates are in their living rooms on television – and on their mobile phones – everyday, so they don’t need someone to tell them how to vote.

Voters do rely on what political scientists call a “voting cue” in a race where they don’t know any of the candidates. In those cases, party, gender, race or endorsements may matter. But presidential races are very different than down-ballot races in the amount of information voters possess.

As a general rule, endorsements in a presidential contest matter only when they are counter-intuitive. A Republican nominee endorsed by a traditionally Democratic interest group or officeholder can use that endorsement to define himself and the choice voters face. That might allow him to woo ticket-splitters and soft partisans of the other party.

But Republicans (or gun owner rights activists, business interests or conservative groups) endorsing Republicans means little. That is simply what is expected.

House Speaker Paul Ryan’s recent comment that he will vote for Donald Trump was noteworthy only because it was so slow to come and so lacking in enthusiasm. “I will vote for him” is not exactly a memorable rallying cry. It is more like a grudging acceptance of the reality of politics and the role of a party leader.

Given the pressure on him to back his party’s presumptive nominee, Ryan’s delay in endorsing Trump was much more significant than his endorsement.

The enthusiastic endorsement of Clinton by President Barack Obama and Massachusetts Sen. Elizabeth Warren were equally expected and also don’t change the fundamentals of the general election contest.

Obama, Warren and Vermont Sen. Bernie Sanders – when he eventually endorses the presumptive Democratic nominee – can help energize the Democratic and liberal faithful in November because of their unique influence with Democratic voters who distrust Clinton. But their impact on Democratic turnout depends on their effort on Clinton’s behalf, and even then, Trump’s candidacy is likely to be a greater motivator of Democrats.

Vice presidential selections are equally over-valued by the media in terms of their impact on the election.

Every four years around this point in the election cycle, the cable networks begin their suffocating coverage of possible running-mates, which will only be interrupted by the latest missing airplane or zoo-related tragedy.

It’s true that vice presidential picks can tell you something about the presidential nominees’ values, priorities and political concerns. And since eight sitting vice presidents succeeded to the nation’s top job after the death of the president, the office itself isn’t trivial. That’s why the nominations are important and deserve media attention. (Clinton will be 69-years-old and Trump 70 on Election Day.)

But few presidential elections are won or lost because of a running-mate. The only modern exception may be 1960, when vice presidential nominee Lyndon Johnson helped Democrat John F. Kennedy carry Texas and win the White House.

Other nominees were controversial or possibly even damaging, including Missouri Sen. Thomas Eagleton (D) in 1972 (who later withdrew), Indiana Sen. Dan Quayle (R) in 1988 and Alaska Gov. Sarah Palin (R) in 2008, but they didn’t change the outcome of the election.

Despite all the media speculation and chatter (both before and after the selections), few voters base their presidential vote on the running-mates. Given all of the coverage of Trump and Clinton over the next five months, it isn’t surprising that voters see the election as a choice between the two presidential nominees.

And of late, vice presidential nominees can’t even guarantee that they will carry their home state. Wisconsin went for Obama in 2012 even with Ryan on the GOP ticket, and Democrat John Kerry didn’t carry North Carolina in 2004 even with John Edwards as his running-mate.

If the folks in Wisconsin and North Carolina didn’t care enough to vote for their home state nominees, why should anyone else?

So, why all the attention to the selection of the vice-presidential picks if they don’t affect the election’s outcome?

Selecting a running-mate is something about which everybody can have an opinion. And because of that, the cable television networks can have an endless supply of talking heads to fill all that air time that needs filling.

So, enjoy the parlor game of first guessing who the running-mates may be, and then chewing over the strengths and weaknesses of the eventual selections. Just don’t expect the selections to have much of an impact in November unless something odd happens.

And given this year’s campaign, what’s the chance of that?

Stuart Rothenberg writes about the politics of the presidential and congressional races.