And on Tuesday, both of those efforts took a significant hit.
Trump should have had a good night on Tuesday, and he did. He'll almost certainly end up with over 100 more pledged delegates -- not enough to clinch, but taking a big chunk out of the remainder that he needs in order to do so. Paired with his giant win in New York a week ago, he's pretty much guaranteed another week of discussion about how likely it is that he'll be the nominee.
That chatter is itself helpful to Trump, for the reason above. The more that Republican voters hear about how strong a candidate Trump is, the harder it will be to convince them that it's okay if he doesn't get the nomination after the second ballot of voting in an arena in Cleveland. Shortly before the New York primary, NBC News and the Wall Street Journal released a poll showing that nearly two-thirds of Republicans thought whoever had the most votes should be the nominee. Trump's six uninterrupted wins since then is unlikely to change that sentiment.
But there's another factor at play here. As Nate Silver notes, Trump's actually doing far better in Tuesday night's contests than polling suggested.
We can compare the latest Real Clear Politics polling averages in the three biggest states to the exit poll estimates for Trump as of 9 p.m. on Tuesday. (These figures may change.) Trump is outperforming in all three, by wide margins.
To win all of Connecticut's delegates, he needed to win each of the state's congressional districts. He has big leads in all five.
What's more, Trump's seen recent spikes in his national polling average and his polling in the critical state of California, which is likely to decide whether he gets to 1,237 delegate on the final day of the nominating contest, June 7.
There have been fewer of these surveys recently, thanks to where we are in the primary process. But the increase is obvious.
There's a direct effect of Trump's improved performance in tonight's primaries: More delegates. The percentage of the remaining delegates that Trump needs to win will drop more than we might have expected. If Trump continues to outperform -- including in Indiana next week, which should be friendlier turf for Ted Cruz -- it has that indirect effect of convincing Republicans that there's not much point in putting up the fight.
In March, we wondered if the anti-Trump forces could hold strong for four more months. If the establishment decides to circle the wagons around Trump, winning more delegates may not matter. For example, most of Pennsylvania's delegates are unpledged. Trump winning the state by a large majority makes it harder for those delegates to stray to someone else -- and may offer party leaders an card to play on Trump's behalf.
With the exception of a win in the tiny Northern Mariana Islands, Donald Trump hadn't broken 50 percent in any state until last week. Since then, he's broken 50 percent six times (assuming percentages in April 26 states hold as they seem to be). Six times in six states.
Whether or not Trump has gotten a lot stronger doesn't really matter. If voters think that he is -- if they think he's got the nomination in hand -- that may be as good as the real thing.