1. You can't beat somebody with nobody, and Donald Trump is running against a couple of nobodies in the Republican presidential primaries—at least as far as East Coast voters are concerned. Ted Cruz's brand of southern conservatism just doesn't play well among the Republicans of the eastern seaboard, and John Kasich is barely running a campaign at all (he has won fewer delegates than Marco Rubio, who dropped out of the race six full weeks ago after a series of humiliating defeats). Trump racked up landslide margins in all five states voting last night, giving him enough delegates that he remains in sight of gaining an overall majority by the end of the primary season.
2. There may be less "momentum" than usual this year, defined as shifts in voter support from one candidate to another based on the results of the sequential primaries. However, any organized effort to block a Trump nomination depends on a perceived possibility of success, and Trump's five-state sweep last night is a body blow to the morale of the "Never Trump" movement. If he manages to win Indiana next week, he may even attain the status of "presumptive nominee."
3. It's likely that the less frenzied election schedule in the back half of the primary calendar has helped Trump on balance. The shock of his early success has worn off, and with no debates and fewer incidents of physical violence at his campaign rallies over the last few weeks, he has succeeded in entrenching himself as the familiar front-runner while Cruz and Kasich have struggled for attention. Trump might not have reached such a secure position in the race if prominent conservatives had used the last month-and-a-half to build a public case against him. But with DC favorite Marco Rubio out of the race after March 15, the only serious remaining alternative to Trump in the race was Cruz, and it's clear that few influential Republicans were interested in risking their own standing within the party only to benefit the junior senator from Texas.
4. Pennsylvania is worth keeping an eye on when calculating the overall Republican delegate count. Under state party rules, most of the state's delegates are officially unbound to any candidate. It appears, however, that the Trump campaign succeeded in electing many of its supporters to delegate slots, while a number of other delegates have promised to vote for the winner of the state or congressional district (which would also be Trump, who carried every district in Pennsylvania). Trump's numerical path to an overall majority is much easier if he can count on another 30 to 40 delegates beyond his official pledged delegate haul from the ranks of the Pennsylvania delegation.
5. Who was the last non-incumbent presidential candidate who easily captured the nomination of a major party and began the general election as the overwhelming favorite to win the White House? I'm not sure of the answer (even Franklin D. Roosevelt, though the clear front-runner in 1932, needed four ballots to be nominated due to the two-thirds vote required by the Democratic convention at the time), but both of these criteria surely apply this year to Hillary Clinton now that it is likely that she will face Trump in November. To hear much of the press tell it, though, she is in big trouble. Channel-flipping last night brought me to a panel of MSNBC reporters moderated by Chuck Todd who went on and on about Clinton's political weaknesses and the prospect of Bernie Sanders-supporting millennials deserting her in favor of Trump in the general election. One does not need to be a Clinton admirer to admit that, by all objective evidence, she is at this moment far and away the most likely person to become the 45th president of the United States next January, yet much of the news media is completely unable to acknowledge her good fortune—much less give her any credit for bringing it on herself with the application of political skill.
We are headed into a general election in which one nominee may have a steady and significant lead for the entire length of the campaign even as the press constantly warns that she is susceptible to defeat by the other party (which is, incidentally, busy tearing itself apart as it nominates a highly flawed candidate). Nothing is guaranteed in electoral politics, but a congenitally Trump-hyping media universe has not yet come to terms with his unprecedented weaknesses in appealing to a broader electorate outside the Republican primaries, and a press corps that has long been suspicious of Hillary Clinton is routinely inclined to overstate her political vulnerabilities.